Airport Site Quickly Being Reduced To Rubble

On the far side of the old Stapleton International Airport in Denver, Colorado, piles of crushed concrete and old asphalt rise in a kind of moonscape.

Nearby lies a tangled heap of steel bars and poles pulled from the concrete rubble.

Trucks hauling 25 tons of concrete in a single load race down runways once used by giant jetliners. Every 90 seconds they dump a load of concrete chunks into a roaring crusher, where a powerful magnet -- capable of pulling a shovel out of your hands -- rips steel from its concrete bed.

Over the next 20 years, the old airport's 4,700 acres will be turned into a new neighborhood with 12,000 homes, 13 million square feet of offices and retail space, and 1,100 acres of parks and open space.

But that's the future.

Mark Wachal's job as president of Recycled Materials Co. Inc., based in Arvada, is to clear away and crush the 6 million tons of concrete and asphalt that paved Stapleton. That includes roads, runways and unneeded buildings torn down to make way for the new development.

The size of the project is staggering.

"It's the largest recycling project in the world," Wachal said.

The concrete and asphalt at Stapleton averages 24 inches thick spread across 1,000 acres -- more than three times the size of City Park.

At its thinnest, it's a few inches. At the thickest point, it's 5.5 feet deep. A "guillotine" rolls across the old runways breaking pavement by dropping a 13,000-pound weight every six seconds 6 inches apart.

Six million tons of rubble are expected to be produced at Stapleton. A typical concrete and asphalt crushing and recycling project produces 100,000 tons.

Recycled Materials, which expects revenues of $12.5 million this year, started work at Stapleton about 2 1/2 years ago. The company has contracted to finish breaking up the rubble in 4 1/2 years. All of it, every single rock, boulder or pile of sand, must be gone from Stapleton in 7 1/2 years.

About 60 percent of the business, which includes crushing and reusing highway and building materials, consulting and highway construction, is dedicated to the Stapleton project, Wachal said.

"We started by the terminals and now we're heading east on the runways," he said. "By this time next year we'll be at I-70; all the concrete south of there will be gone."

Everything must be done by 2009 and to stay on schedule, 175 acres of pavement -- an area larger than Washington Park -- must be removed every year.

Recycled concrete and asphalt is being used at Denver International Airport. Some is headed for the Rocky Mountain Arsenal. Some is already being returned to Stapleton as new roads are built.

"Our whole mission is to be able to produce the highest quality and the highest valued product," said Wachal. "We're trying not to waste any product out here."

Wachal has been working on the recycling of Stapleton since 1993, when he joined a committee pondering the possibilities of the still-operating airport.

Where many people saw a paved wasteland to be hauled to the dump, Wachal saw an urban mine filled with high-quality asphalt and concrete originally constructed to meet Federal Aviation Administration standards. And this mine isn't located in the foothills, it's in the heart of the city, close to paving projects at DIA as well as projects in and around Denver.

"We call this our urban quarry," Wachal said. "It's 1,000 acres, but only 2 feet thick, but it's built with high quality aggregates."

It's an attitude that city officials in the mid-1990s liked as they planned Stapleton's future.

What to do with all the pavement at Stapleton was a "huge issue," recalled Jeannine Balsamo, former director of asset management for the nonprofit Stapleton Development Corp.

"It's 6 million tons of concrete. There had to be a way to get rid of that without disturbing the community," Balsamo said.

"We were looking for an entrepreneurial plan from someone who could come in and put a lot of money into it up front and take all the risk of getting rid of the stuff," she said.

Recycled Materials believed it could find customers to use the crumbled airport, and per its contract isn't taking a dime from the city for the demolition work. Wachal figures breaking up the runways and roads at Stapleton is a $30 million job that the city is getting for free.

The company makes its money selling the crushed rubble -- from flat "Staplestone" pieces 4 feet to 5 feet across and 16 inches thick to nuggets of gravel and even grains of sand.

"We had some large customers who were interested, but they also had a reluctance to make a change," Wachal said.

Contractors in the road construction industry routinely recycle old asphalt into new roads. But they traditionally view recycled concrete as inferior to virgin aggregate freshly mined for a project.

In 1996, students at the Colorado School of Mines tested the theory, creating ready-mix concrete made from virgin and recycled aggregate. There was no difference, Wachal said.

"We knew that it would work and it would make the project economically viable," he said. The company also benefited its experience in highway construction -- company executives spoke the lingo of highway designers and contractors.

Recycled Stapleton concrete and asphalt sells for $1 to $2 more per ton than virgin aggregate, but becomes economical due to its location, Wachal said. Hauling the aggregate to a project from Stapleton is cheaper than hauling it from mines in the foothills.

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But he had to convince the customers.

The city and county of Denver has been helpful in encouraging its agencies to use the recycled products, he said.

And Aggregate Industries - West Central Region Inc., one of the largest aggregate producers and users on the Front Range, is a customer.

"They've really done a terrific job out there," said company President Jim Addams.

Although at the start, Addams admits his company wasn't "particularly imaginative" about using recycled concrete.

"I've been in the aggregate industry for 20 years and always believed the stories that you can't use recycled concrete to make concrete, that you could only use it for a base under the concrete," Addams said. "But those guys do a good job making a good, uniform product. It's every bit as good a product as virgin aggregate."

Aggregate Industries has since committed to buying 22,000 tons per year from Recycled Materials, Addams said.

Another big customer is the Rocky Mountain Arsenal. The arsenal's towering pile of rubble consists of white rocks bigger than a basketball and fenced off with warning signs. The crushed concrete is called "Biota" meaning "of the earth," Wachal said.

When complete the pile of Biota -- just one of 12 different products Stapleton is producing -- will cover 12 acres and rise 70 feet in the air, Wachal said.

It's waiting until the arsenal is ready to dump the rubble on top of contaminated areas. The concrete chunks are so big and heavy rodents can't dig underneath them, said Ruth Mecham, chief of public affairs for the Army at the arsenal.

"It's a win-win for everybody," Mecham said. "We're using recycled material and it's close to us. It makes good sense, rather than trucking [aggregate] from the mountains."

For Wachal, the best part is seeing a great idea become reality.

"What I think is neat is seeing a plan we've been working on since 1993 coming together," he said.. The Denver Business Journal