What it takes to blow stacks

  • Demolition estimate: $750,000
  • Asarco stack one of world’s tallest
  • Concrete tower marked by gunfire

By Sito Negron – El Paso Inc.

The big stack at Asarco – the one that stands 828-feet tall – almost certainly is going to come down in a big explosion and a huge cloud of dust.

The demolition will probably happen on a Sunday morning to minimize disruptions. Even then, both Interstate 10 and Paisano Drive would be closed for safety reasons.

Site trustee Roberto Puga is already taking bids for demolition of the big stack and two others, measuring 610 and 300 feet.

“The tall stack is one of the highest in the world,” Puga said. “This would be an absolute premium job for the explosives contractor.”

And like other tall and visually prominent structures along the border, it’s been hit by its share of gunfire.

“The stack has many bullet pockmarks on the side facing Mexico,” Puga said. “I guess it’s a favorite for target practice.”

The plan calls for all the structures on the site to be demolished, which includes huge warehouses and furnace buildings the size of small stadiums, and about 100 smaller buildings and rigs.

The general demolition could begin as early as this October or November and take about a year, with the stacks the last to come down.

Puga said the estimate for demolishing everything is about $8.9 million for, including $750,000 for the stacks.

Topple like a tree
The demolition itself will have three elements, Puga said: the explosives, water to keep dust from escaping, and air monitors set up to check whether any particles escape.

Explosives will be set to blow inward, making a notch near the base so the tower topples like a tree. Puga said the stack will be wrapped and fall into a bed of sand as part of the effort to keep chunks from flying out or particles from escaping.

Work on the 828-foot stack began in 1964 and finished in 1966 at a cost of about $1.4 million, said Ed Santiesteban, a former plant worker who now is part of Puga’s team, and has become an unofficial smelter historian.

The stack was built in sections, pouring concrete over steel held in molds all the way to the top. It’s ringed by three catwalks that allow access to warning lights and other equipment.

The big tower is actually two smokestacks, with a smaller tube inside the visible structure, and was built with 162 miles of steel and 846 tons of concrete. It’s a little more than 30 feet wide at the base, where a small steel door allows access.

A constant air pressure shoots up the stack, strong enough to have buckled the door inward.

All three stacks will come down at once, said Puga. The 610-foot structure was used for the lead smelter that closed in 1985. The 300-foot steel stack was connected to the acid plant.

Cost to keep it
El Pasoans generally favor keeping the big stack. Some see it as an historic piece of El Paso’s industrial history, a tribute to the workers, or a massive piece of art. But plenty others see it as symbolic of the pollution the plant produced and want it torn down.

The biggest thing working against preservation is the cost, estimated by Puga as more than $10 million to stabilize the concrete and steel structure, and thousands more each year to maintain the piece.

“I’m all for it if someone steps forward to pay for upkeep and keep it safe,” Puga said. “One reason to leave (the stacks) to the back end of demolition is to give the city or whoever is interested time to mount that effort.”

Puga was hired by the Texas Commission on Environmental Quality to serve as trustee for the Asarco Texas Custodial Trust. The trust was created in the December bankruptcy settlement that ended years of expensive litigation over the company’s future.

For El Paso, $52 million was set aside from the $1.8 billion overall paid by Asarco for settling environmental claims and other debt.

The $52 million in El Paso is to pay for cleaning a pool of contaminated water under the site and capping the place in concrete, among other items.