In a sealed room behind armed guards and three rows of tall barbed wire at the Army’s Pueblo Chemical Depot in Colorado, a team of robotic arms were busy dismantling some of the United States’ last vast and terrifying stockpile of chemical weapons.
Artillery shells filled with deadly mustard, which the army had stored for more than 70 years, were arriving. The bright yellow robots pierced, emptied and washed each tray, then baked it at 1,500 degrees Fahrenheit. Out came inert and harmless scrap metal, which clattered off a conveyor belt and dropped into an ordinary brown dumpster.
“That’s the sound of a chemical weapon dying,” said Kingston Reif, who has campaigned for disarmament outside of government for years and is now deputy assistant secretary of defense for threat reduction and arms control. He smiled as another grenade rattled into the Dumpster.
Destroying the stockpiles has taken decades and the army says the work is all but complete. The depot near Pueblo destroyed its last gun in June; The remaining handful at another depot in Kentucky will be destroyed in the next few days. And when they’re gone, all of the world’s publicly declared chemical weapons will be gone.
The American stockpile built up over generations was shocking in its scale: cluster bombs and landmines full of nerve agents. Artillery shells that could shroud entire forests in a glowing, mustard-colored haze. Tanks full of poison that could be loaded onto nozzles and sprayed at targets below.
It was a class of weapon considered so inhumane that its use was condemned after World War I. Still, the United States and other powers continued to develop and accumulate them. Some possessed deadlier versions of the chlorine and mustard chemicals notorious in the western front trenches. Others possessed later-developed neurotoxins such as VX and sarin, which are deadly in minute amounts.
It is known that American forces have not used deadly chemical weapons in combat since 1918, despite using herbicides such as Agent Orange, which were harmful to humans, during the Vietnam War.
The United States also once had an extensive biological warfare and biological weapons program; These guns were destroyed in the 1970s.
The United States and the Soviet Union agreed in principle to eliminate chemical weapons stockpiles in 1989, and when the Senate ratified the Chemical Weapons Convention in 1997, the United States and other signatory countries committed to eliminating chemical weapons once and for all.
But destroying them wasn’t easy: they were built to be fired, not dismantled. The combination of explosives and poison makes them extremely dangerous to handle.
Defense Department officials once predicted that the task could be completed in a few years and the cost would be about $1.4 billion. It’s now decades behind schedule and costing nearly $42 billion — 2,900 percent more than budgeted.
But it’s done.
“It was certainly an ordeal — I wondered if I would ever see that day,” said Craig Williams, who began campaigning for the camp’s safe destruction in 1984 after learning the Army was stockpiling tons of five chemical weapons Miles from his home at the Blue Grass Army Depot near Richmond, Kentucky.
“We had to fight and it took a long time, but I think we should be very proud,” he said. “This is the first time in the world that an entire class of weapons of mass destruction has been destroyed.”
Other powers have also destroyed their declared stockpiles: Britain in 2007, India in 2009, Russia in 2017. However, Pentagon officials warn that chemical weapons are not yet completely eradicated. Some countries never signed the treaty and some, notably Russia, appear to have kept undeclared stocks.
Nor did the treaty end the use of chemical weapons by rogue states and terrorist groups. Forces loyal to Syrian President Bashar al-Assad used chemical weapons in the country on multiple occasions between 2013 and 2019. According to IHS Conflict Monitor, a London-based intelligence gathering and analysis service, Islamic State fighters used chemical weapons at least 52 times in Iraq and Syria from 2014 to 2016.
The vast American stockpile and decades of effort to dispose of it are both a monument to human folly and a testament to human potential, say those involved. The work took so long in part because citizens and legislators insisted that the work be carried out without endangering the surrounding communities.
In late June, workers at the 15,000-acre Blue Grass depot carefully pulled fiberglass shipping tubes containing sarin-filled rockets from earth-covered concrete storage bunkers and drove them to a series of buildings for processing.
Inside, workers wearing hazmat suits and gloves scanned the tubes to see if the warheads inside were leaking, then sent them down a conveyor belt to their demise.
It was the last time people handled the guns. From there, robots did the rest.
Chemical munitions all share essentially the same design: a thin-walled warhead filled with liquid warfare agent and a small explosive charge to rupture it on the battlefield, leaving behind a spray of small droplets, mist and vapor – the “poison gas” over which Soldiers feared from the Somme to the Tigris.
For generations, the American military vowed to only use chemical weapons in response to an enemy chemical attack—then set about amassing so many that no enemy would dare. By the 1960s, the United States had a top-secret network of manufacturing facilities and storage complexes around the world.
Little did the public know just how large and deadly the stock had grown until one snowy spring morning in 1968, 5,600 sheep mysteriously died on land near an Army proving ground in Utah.
Under pressure from Congress, military leaders admitted the Army had tested VXs nearby, that it stockpiled chemical weapons at facilities in eight states, and that it was testing them in the open at several locations, including a site 25 miles away in Baltimore.
When the public learned the scope of the program, the long road to destruction began.
At first, the Army openly wanted to do what it had been secretly doing for years with obsolete chemical munitions: load them onto obsolete ships and then sink the ships at sea. But the public reacted with anger.
Plan B envisaged burning the stocks in huge incinerators – but this plan also met with resistance.
Mr. Williams was a 36-year-old Vietnam War veteran and carpenter in 1984, when Army officials announced nerve gas would be burned at the Blue Grass depot.
“A lot of people asked questions about what would come out of the stack and we didn’t get any answers,” he said.
Outraged, he and others organized opposition to the incinerators, lobbying lawmakers and enlisting the help of experts who argued that the incinerators were emitting toxins.
Incinerators in Alabama, Arkansas, Oregon and Utah, and one on Johnston Atoll in the Pacific, were used to destroy much of the stockpile, but activists blocked them in four other states.
Under orders from Congress to find another way, the Department of Defense developed new techniques to destroy chemical weapons without burning them.
“We had to figure it out over time,” said Walton Levi, a chemical engineer at the Pueblo Depot who started field work after college in 1987 and now plans to retire once the last cartridge is destroyed.
In Pueblo, each bowl is pierced by a robotic arm and the mustard inside is sucked out. The shell is washed and baked to destroy any remaining traces. The mustard active ingredient is diluted in hot water and then broken down by bacteria in a process similar to that found in sewage treatment plants.
It creates a residue consisting mostly of ordinary table salt, Mr Levi said, but laced with heavy metals that must be treated as hazardous waste.
“Bacteria are amazing,” said Mr. Levi as he watched grenades being destroyed in Pueblo on the final day of operations. “Find the right ones and they’ll eat almost anything.”
At the Blue Grass Depot, the process is similar. Liquid nerve agents discharged from these warheads are mixed with water and caustic soda, and then heated and stirred. The resulting liquid, called hydrolyzate, is trucked to a facility outside of Port Arthur, Texas, where it is incinerated.
“It’s a good bit of history that we’ve got behind us,” said Candace M. Coyle, Army project manager for the Blue Grass depot. “The best part is that it doesn’t harm anyone.”
Irene Kornelly, chair of the Citizens Advisory Commission that has overseen the Pueblo process for 30 years, has kept track of how nearly a million mustard shells were destroyed. Now 77 years old, she stood leaning on a cane and craned her neck to watch as the last cane was scrapped.
“Honestly, I never thought this day would come,” she said. “The military didn’t know if they could trust the people, and the people didn’t know if they could trust the military.”
She looked around, taking in the beige buildings of the plant and the empty concrete storage bunkers on the Colorado prairie beyond. A crowd of workers in coveralls with emergency gas masks on their waists gathered nearby to celebrate. The plant manager yelled “The Final Countdown” over the PA system and handed out red, white, and blue bomb pops.
Mrs. Kornelly smiled as she took it all in. The process was smooth, safe and so tedious, she said, that many residents of the area forgot it was happening.
“Most people today have no idea that any of this happened — they never had to worry about it,” she said. She paused, then added, “And I think that’s a good thing.”