Cleaning Up the Past

Early in 2006, Aberdeen Proving Ground in Maryland became the first continental U.S. military site to eliminate its stockpile of chemical weapons. It was an important milestone for the country, and also for Bechtel, which has led the effort at Aberdeen and is involved in similar chemical demilitarization projects at two other U.S. military sites—Colorado’s U.S. Army Pueblo Chemical Depot and the Blue Grass Army Depot in Richmond, Kentucky.

Though never used by the United States, chemical weapons were stockpiled at a number of army bases during and after World War II. In 1985, Congress decided that the time had come to turn the feared and dangerous chemical weapons into a harmless part of history.

It’s a complex job that involves designing, building, and operating facilities to neutralize the agent; dismantling the facilities when the work is complete; and then restoring the land for other uses. The nature of the work makes it unique for Bechtel, says Joe Nemec, the company’s chemical demilitarization operations manager. “We don’t usually get involved in projects where we build something and then have to tear it down,” he says.

At Aberdeen, where the stockpile dated to 1942, the Bechtel team drained more than 1,800 drum-shaped canisters containing a total of some 1,450 tonnes of mustard agent in liquid form. Workers then mixed the mustard agent with heated water in titanium reactors, and the resulting neutralized liquid was shipped to a DuPont plant in New Jersey for additional treatment and disposal.

Construction of the neutralization facility at Aberdeen had just passed the halfway point when America suffered the terrorist attacks of September 11, 2001. Mindful that unused chemical weapons could be a potential terrorist target, the Army asked Bechtel National engineers to accelerate the chemical demilitarization program.

The decision was made to scale back construction and carry out the neutralization using equipment already in place. “In three months, we completely redesigned the project to use structures already on-site,” says Bechtel Project Manager Mark Seely.

The destruction sequence also was changed. Instead of cleaning each canister immediately after draining it, the new plan called for draining all of the canisters first, then cleaning them after all of the agent had been neutralized. The cleaned canisters are cut apart and the steel recycled.

Bechtel National employees took the changes in stride and finished eliminating the mustard agent nearly a year ahead of schedule. With the main task accomplished, crews now are focused on decontaminating the entire plant site and beginning “reverse construction,” which is expected to be completed in December 2007.

“We’re proud that Bechtel had the privilege to complete the nation’s first stateside chemical demilitarization project,” says Brian Feeney, Aberdeen’s public outreach manager. “After more than 60 years of living with these weapons, the people of Maryland no longer have to be the custodians of this stockpile.”

As Aberdeen winds down to next year’s closing, Pueblo and Blue Grass are gearing up, with early roadwork and other basic site preparation under way. Like Aberdeen, these depots store large quantities of mustard agent. However, their chemicals reside in much smaller projectiles and rockets, and the Blue Grass inventory includes nerve agents.

When demilitarization begins at Pueblo, Bechtel employees will deal with weapons that must be disarmed before the mustard agent can be removed. Says Bechtel Pueblo Project Manager Paul Henry, “The engineering challenge is not in neutralizing the mustard; it’s in the mechanics of removing the explosives and draining the mustard out of each individual artillery or mortar shell.”

Each shell contains just 2.7 to 4.5 kilograms of agent, but there are about 780,000 shells. Construction of the neutralization facility is set for completion in 2009. Demilitarization should begin in late 2011, with a 2016 closeout date.

Munitions also make up the majority of the Blue Grass stockpile, where 100,000 M55 rockets and projectiles await neutralization by the end of 2016. To ensure worker and public safety, disarming will take place in structures with thick, reinforced concrete walls, in case of accidental explosions that could result in a chemical release.

“We try to plan for the unknown,” says Blue Grass Project Manager Chris Haynes. “Aberdeen wrote the book for us as far as lessons learned, but since this is a first-of-a-kind project, the unexpected is always going to come up.”

Even small amounts of the chemicals at Aberdeen, Pueblo, and Blue Grass could prove deadly or cause permanent eye or respiratory damage, which is why Bechtel National engineers added another layer of safety procedures to the demilitarization process. “Safety is one of our main products on every job,” says Nemec. “But at these sites it goes far beyond our traditional zero-accidents policy.”

Before handling chemical materials, all workers receive training to prepare for situations in which they could come in contact with chemicals or where physical barriers fail.

The few accidents that have occurred at the three sites resulted in minor injuries such as twisted ankles and cuts and bruises. Equally important, not one drop of chemical has leaked into the open as Bechtel National puts a deadly reminder of past wars into its safe and final resting place.

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