3. BURSTER 

CASING 

ASSEMBLY

4. AGENT CAVITY

1. FUZE

2. PROJECTILE 

BODY

1. The FUZE contains 

energetics 

(explosives), which 

trigger the burster.

2. The PROJECTILE 

BODY is the outer 

shell of the projectile.

3. The BURSTER CASING 

ASSEMBLY holds the 

burster, which is the 

energetic matter 

that ruptures the 

shell. This process 

also atomizes the 

liquid mustard agent, 

creating a vapor 

cloud.

4. The AGENT CAVITY

is the sealed area 

within the projectile 

where the liquid 

agent is held.

Diagram of a mustard agent projectile. The burster is contained 

completely within the burster casing assembly, so it does not come into 

contact with the mustard agent. This allows the burster to be removed 

without becoming contaminated.

Contact Us

Pueblo

Summer 2002

U.S. Army

Program 

Manager 

for Chemical 

Demilitarization

Make a note...

New outreach 

offi ce location 

and contact 

numbers

Pueblo Chemical Depot 

Community Outreach 

Offi ce

301 North Main Street

Suite 306B

Pueblo, CO 81003

Phone: (719) 546-0400

Fax: (719) 546-0409

Outreach Offi ce Hours

Monday–Friday

8:30 a.m.–5 p.m.

Other hours by appointment

Outreach Offi ce Staff

(719) 546-0400

Pueblo Chemical Depot 

Public Affairs Offi cer

(719) 549-4135

Reach Highlighting

the U.S. Army’s

Chemical 

Demilitarization 

Program

continued on page 2 ...

For years, the Army and the Pueblo community 

worked together to select a safe technology to 

destroy the chemical weapons stored at Pueblo 

Chemical Depot. This coordination led 

to the identifi cation of “neutralization 

followed by biotreatment” as the 

preferred disposal technology. On 

July 18, 2002, Under Secretary of Defense 

Pete Aldridge made this technology selection 

offi cial. A Request for Proposal was released 

on July 26, 2002 to seek bids 

from contractors to develop and 

operate the Pueblo chemical 

weapons disposal facility. Once 

a systems contractor is selected, 

the contractor will have some 

fl exibility in determining specifi c 

aspects of the disposal process. 

What is 

neutralization 

followed by 

biotreatment?

Often referred to as “neut/bio” 

or the “bug method,” this 

technology will use hot water 

to neutralize chemical agent 

and microbes to “eat” the 

resulting hydrolysate. Actually, 

the science of using microbes to 

help in disposing of hazardous 

waste has existed for decades, and the process 

occurs in nature all the time. Sewage treatment 

facilities across the country use microbes every 

day to help break down raw sewage. The Army 

also is using neut/bio for disposing of mustard 

agent stored at Aberdeen Proving Ground in 

Maryland. 

In addition to the hot water and microbes, 

skilled workers and sophisticated robots will 

ensure the safe destruction of Pueblo’s chemical 

weapons stockpile. What follows is a step-bystep explanation of the neut/bio process. These 

steps may be modifi ed by the systems contractor 

with government oversight.

Weapons disposal technology fi nalized

The neut/bio process

Step One: Removing the Explosives

Robotic equipment will remove the weapon’s 

explosive parts including the fuze and the burster 

(see diagram above). Removing the explosive parts 

fi rst makes the remaining processes safer. The 

explosives in the burster will be washed out using 

pressurized water or by soaking in a bath of water 

and caustic solution. This water and explosive 

mixture will be further processed in Step Three. 

Metal parts, including fuzes that contain very 

small amounts of explosives, will be disposed of 

in Step Five.
2

Step Two: Removing the

Mustard Agent

Once the explosive parts are removed, the weapon 

body containing chemical agent will be processed. 

The agent will be removed by accessing the body 

and washing it out with pressurized water. This also 

can be done by freezing the body and fracturing it 

with a press then soaking the metal pieces in water to 

separate the agent.

Step Three: Neutralizing the Energetics 

and Mustard Agent

After the energetics and agent have been separated 

from the metal parts, they will be treated in separate 

tanks with a water and caustic solution. What results 

from this process is called hydrolysate. The energetics 

hydrolysate and agent hydrolysate are then combined 

and further processed in Step Four.

Step Four: Biotreatment

The hydrolysates generated in Step Three will go 

through the biotreatment process, which consists 

... continued from page 1

The Sept. 11, 2001, terrorist attacks prompted the 

Army to look at ways of accelerating the disposal 

process in Pueblo. The neut/bio technology 

explained in the cover story will be used to destroy 

the chemical weapons, but programmatic and 

processing changes are being considered to enable an 

accelerated schedule.

Programmatic changes include accelerating the 

contracting process to get a systems contractor 

in place as soon as possible. Discussions also are 

on going with the state and community to fi nd 

ways of accelerating the permitting process. To 

accelerate the neut/bio process, the early use of 

enhanced reconfi guration (the complete separation 

of energetics from the weapon) is being considered. 

Army and ACWA investigating ways to 

accelerate disposal

Environmental Impact Statements available

The two documents listed below are available in executive summary, hard copy or CD-ROM. To receive a 

copy, contact the outreach offi ce at (719) 546-0400.

• Program Manager for Chemical Demilitarization’s Final Environmental Impact Statement for the 

Destruction of Chemical Munitions at Pueblo Chemical Depot.

• Program Manager for Assembled Chemical Weapons Assessment’s Final Environmental Impact 

Statement for the Design, Construction and Operation of One or More Pilot Test Facilities for 

Assembled Chemical Weapons Destruction Technologies at One or More Sites.

ACWA

Congress created 

the Assembled 

Chemical 

Weapons 

Assessment 

(ACWA) program 

in 1997 to study 

technologies 

other than 

incineration 

for disposing 

of assembled 

chemical 

weapons. 

ACWA recently 

completed that 

mission and 

demonstrated 

that neut/bio is a 

viable technology 

for destroying 

Pueblo’s chemical 

stockpile.

Additionally, the Army and ACWA are considering 

shipping the energetics and/or hydrolysate offsite to existing facilities for disposal. They also 

are investigating shipping uncontaminated 

wooden pallets off-site, as well as decontaminated 

demilitarization protective ensembles—special 

protective clothing worn by workers when around 

chemical agent. The Army has an excellent track 

record of shipping such items safely.

These options are being coordinated with the 

state and the community to determine the most 

appropriate path forward to expedite the destruction 

of the stockpile at Pueblo. These steps would result 

in a shorter construction schedule to expedite 

destruction of the Pueblo stockpile. 

of large tanks containing microbes that digest and 

further break down the solution. Water released from 

the process will be recycled, leaving various salts and 

biosludge. Biosludge, which is made up of microbe 

waste products and dead microbe matter, will be 

dried and shipped off-site to a treatment, storage and 

disposal facility.

Step Five: Disposing of the

Metal Parts

The fi nal step of the destruction process is treating 

the weapon’s metal parts. Although the metals were 

cleansed of agent in Step One, they still may contain 

agent and need to be decontaminated to a higher 

level. This level is called “5X,” a military standard of 

decontamination that ensures the metal is clean and 

safe for reuse. To reach this level of decontamination, 

the metals will be heated to 1,000 degrees Fahrenheit 

for 15 minutes. The metal then can be recycled.

For more information about neut/bio technology, 

please contact the outreach offi ce at 

(719) 546-0400.
3

Stay informed—Stay involved!

Calendar of upcoming meetings and events:

• Colorado Citizens’ Advisory Commission meeting

Sept. 5, Pueblo Convention Center

• Pueblo Chemical Depot Community Outreach Offi ce booth at the Chili and Frijoles Festival

Sept. 20–22, Union Avenue District/Historic Arkansas Riverwalk

• Colorado Working Integrated Product Team meeting

Early October, date and location to be announced

• Agricultural Assessment Working Group meeting

Late October or early November, date and location to be announced

The outreach offi ce sends a weekly e-mail that lists upcoming meetings and events pertaining to chemical 

weapons disposal in Pueblo. If you would like to receive this weekly e-mail, please contact the outreach 

offi ce at (719) 546-0400.

From lessons learned at the Army’s fi rst chemical 

weapons disposal facility located on Johnston Island 

in the Pacifi c, prolonged storage occasionally has 

caused mustard agent to separate in some weapons 

and harden in others.

Like many industrial chemicals, the Army produced 

its chemical weapons in batches or “lots.” Some of 

the weapons stored in Pueblo come from the same 

lots as those on Johnston Island that “frothed” 

when opened—similar to a can of soda fi zzing. This 

unanticipated occurrence contaminated the facility’s 

equipment. In addition, some of the mustard agent 

on Johnston Island had hardened, creating a fi rm, 

gelatin-like “heel” at the bottom of the weapons that 

was diffi cult to remove.

Because it is possible that these conditions may be 

discovered when processing mustard agent at the 

Pueblo facility, the design of the neut/bio process 

will take this into consideration. The weapons can 

be frozen, which solidifi es the agent and prevents 

frothing. The weapons then can be fractured using 

a high force press, and the pieces can be soaked in a 

water bath to remove the agent. The munitions also 

can be accessed in equipment designed to contain 

the frothing agent, leaving the remaining agent to 

be washed out using a water spray. The neut/bio 

process then would continue as described on pages 

one and two. 

The Army will work closely with the Pueblo facility’s 

systems contractor, environmental regulators and 

the community to identify safe methods to access 

deteriorated mustard agent. 

Prolonged storage has deteriorated some 

mustard agent

REACH ABCs

Below is a list of 

all the acronyms 

used in this issue 

of the REACH 

newsletter:

• ACWA

Assembled 

Chemical 

Weapons 

Assessment

• CAC

Citizens’ 

Advisory 

Commission

Mustard 

Agent 

Quick Fact

Contrary to 

common thought, 

mustard agent 

is not a gas. It 

is a thick liquid 

that resembles 

molasses. 

Mustard is a 

blister agent that 

was designed to 

infl ict chemical 

burns on enemy 

troops. The 

purpose was 

to cause injury, 

not death. The 

U.S. Army never 

used its chemical 

stockpile and 

is working to 

destroy these 

aging weapons 

safely. When mustard agent originally was inserted into 

weapons and storage containers in the 1950s, it was 

a clear, thick liquid. Prolonged storage has corroded 

the agent into a brown substance that resembles 

molasses, as seen in the laboratory container 

pictured above.
Pueblo Chemical Depot Community Outreach Offi ce

301 North Main Street, Suite 306B

Pueblo, CO 81003

#

The Pueblo Chemical Depot Community 

Outreach Offi ce serves as a clearinghouse 

of information concerning the Army’s plans 

for chemical weapons disposal in Pueblo. 

Together with the depot’s Public Affairs 

Offi ce, the outreach offi ce coordinates 

a variety of events designed to keep the 

community informed and involved.

If you would like more information about 

the opportunities available through the 

Pueblo Chemical Depot Community 

Outreach Offi ce, please call (719) 546-

0400, or return this form by mail to:

Pueblo Chemical Depot Outreach Offi ce

301 North Main Street, Suite 306B

Pueblo, CO 81003

Please check the boxes that interest you:

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If you checked any of the boxes, please complete the following:

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Reach