Destroying nerve and mustard agents

As part of the ratification of the 1997 Chemical Weapons Conventions, an international treaty to destroy chemical weapons and production facilities, a Bechtel-led team was contracted in 2003 to help the United States complete its obligations under this treaty. Under this U.S. Department of Defense contract, Bechtel Parsons Blue Grass, a joint venture of Bechtel National and Parsons Government Services, will design, build, systemize, test, operate, and close the first–of–a–kind plant to safely destroy the weapons stockpile at the Blue Grass Army Depot in Richmond, Kentucky. The Blue Grass Chemical Agent-Destruction Pilot Plant will destroy 523 tons of nerve and mustard agent within 100,000 M55 rockets and artillery projectiles stored at the Blue Grass Army Depot in Kentucky. 

For more information visit the Bechtel Parsons Blue Grass website.

Bechtel has tackled four chemical demilitarization projects at U.S. military sites: Blue Grass Chemical Agent-Destruction Pilot Plant, Kentucky (ongoing); Pueblo Chemical Agent-Destruction Pilot Plant, Colorado (ongoing); Anniston Chemical Agent Disposal Facility, Alabama (completed); and Aberdeen Chemical Agent Disposal Facility, Maryland (completed).



In June of 2019, the Blue Grass plant began processing chemical weapons in its Static Detonation Chamber, marking the beginning of the end for the last chemical weapons stockpile remaining in the U.S.

The first munition destroyed at the Blue Grass site was a World War II-era 155-millimeter artillery projectile containing mustard agent. This control-room monitor shot shows technicians loading the projectile for processing on June 7, 2019. The last mustard projectile was destroyed September 4, 2021.



The first projectile containing the nerve agent GB was destroyed in the Main Plant at Blue Grass in January 2020. The last of the nearly 4,000 8-inch projectiles were destroyed five months later. In January 2021, the process to destroy approximately 13,000 VX nerve agent projectiles began in the same facility. This campaign completed in May 2021.

Just three months later, the first M55 VX rockets were processed in the plant. This campaign is expected to conclude in the spring, 2022. The last campaign at Blue Grass will be the destruction of more than 51,000 M55 rockets containing the nerve agent GB, expected to begin in the summer of 2022. The GB rockets make up around half of the total weapons stockpile at Blue Grass.

Long history

Long history

Construction of the neutralization facility at Aberdeen—the first such project—had just passed the halfway mark when America suffered the terrorist attacks of September 11, 2001. Mindful that unused chemical weapons might be a terrorist target, the U.S. Army asked Bechtel to accelerate the chemical demilitarization program. The project team managed to finish eliminating the mustard agent at Aberdeen a year ahead of schedule.

Image gallery

What are chemical weapons?

Contrary to popular belief, the chemical agents being destroyed at Blue Grass are not gases. In their original form, they are liquids. When stored for a long period of time, they can become thick and sludge-like. Destroying chemical weapons benefits everyone with greater safety and security—physical as well as environmental—and puts an end to costs associated with managing the stockpile over the long haul.

How the weapons are destroyed.

The stockpile at the Blue Grass depot are being destroyed in two ways.

The projectiles containing mustard agent were destroyed in a Static Detonation Chamber that used heat to consume the toxic material. Any exhaust was filtered through a complex filtration system.

For the projectiles containing nerve agents, specialists operating sophisticated robotic machinery disassembled the munitions and extracted the chemical agent. Using a mix of caustic and hot water, the team chemically neutralized the agent, rendering the liquid material as hydrolysates.

The hydrolysates are held and monitored to confirm agent destruction and then shipped to a permitted hazardous waste treatment, storage, and disposal facility for further processing in accordance with environmental permitting.

After the agent was drained from them, the projectiles were thermally decontaminated and metals parts were safely recycled.

For GB and VX rockets, following the drainage of the agent, the warheads are placed in containers and sent for temporary storage in igloos at the Blue Grass Army Depot. They will be destroyed in a Static Detonation Chamber unit at a later time. Rocket motors are packed in boxes and temporarily stored until they are shipped to Anniston, Alabama where they will be destroyed in a Static Detonation Chamber at that facility.

Destruction of Chemical Weapons Underway

Destruction of blister agent began in 2019 at the Explosive Destruction Technology (EDT) facility. 

The EDT destroyed the entire stockpile of mustard projectiles, due to the liquid agent becoming thick and sludge-like. The Static Detonation Chamber mentioned above electrically-generated heat at more than 1,000°F to detonate or deflagrate the munitions, destroying the agent.

Destruction of projectiles containing nerve agents GB and VX began in January 2020. The last of the 155mm projectiles containing VX nerve agent was destroyed in May 2021.

The first rocket containing VX nerve agent was destroyed July 2021. The destruction of the rockets containing GB agent is anticipated to begin in the summer of 2022.

Agent destruction will be completed in 2023, based on the current schedule and Department of Defense funding. Eventually, the team will perform an environmental closure of the facility.

What happens after the weapons are destroyed?

The areas of the facility that have come in contact with a chemical agent will be decontaminated and the equipment dismantled. The disposition of the remainder of the facility has not yet been determined and will be negotiated by representatives of the Commonwealth of Kentucky, the Assembled Chemical Weapons Assessment program, and Blue Grass Army Depot.