Facts: Pueblo Chemical Agent-Destruction Pilot Plant Closure Overview

The Pueblo Chemical Agent-Destruction Pilot Plant, or PCAPP, has completed the destruction of the chemical weapons stockpile at the U.S. Army Pueblo Chemical Depot, known as PCD, in Pueblo, Colorado. The U.S. Department of Defense’s Program Executive Office, Assembled Chemical Weapons Alternatives, or PEO ACWA, was responsible for the safe and environmentally compliant destruction of these weapons and closure of the destruction facilities. The program’s priority is the safety of the workforce, neighboring communities and the environment. The program targeted destruction of the stockpile by the Chemical Weapons Convention, or CWC, treaty commitment of Sept. 30, 2023. U.S. Public Law mandates stockpile destruction by Dec. 31, 2023.

The Pueblo plant consists of two destruction facilities and associated support buildings:

  • The main plant destroyed mustard agent contained in 4.2-inch mortar rounds and 155mm and 105mm projectiles.
  • The Static Detonation Chamber (SDC) complex destroyed munitions that are not practical for processing in the main plant.

Once the chemical agent stockpile is destroyed, agent-related material, such as empty munition bodies and Brine Reduction System (BRS) solids, must still be eliminated. Such items are considered secondary waste but are tracked to destruction by international verification inspectors with the Organisation for the Prohibition of Chemical Weapons. The empty munition bodies and BRS solids will be sent off site for disposal at a permitted Treatment, Storage and Disposal Facility (TSDF) approved under the Resource Conservation and Recovery Act (RCRA).

After destruction operations are complete, the facilities will be closed in a safe, environmentally protective and compliant manner. The process of chemical agent destruction facility closure involves five major factors and is sequenced to occur in compliance with all permits, regulations and requirements. These include:

  1. Decontamination: removal of residual chemical agent contamination to safe and environmentally protective levels, as prescribed by permits.
  2. Decommissioning: rendering equipment safe for removal and eventual demolition or future use.
  3. Dispositioning: transfer of government personal property for reuse, sale, recycling or disposal; and reconfiguring real property for PuebloPlex, the local redevelopment authority for PCD.
  4. Demolition: removal of facilities not required for future use.
  5. Administrative closeout: closure of environmental permits, closing of contracts and interagency agreements and archiving of records.

Facility-specific closure information follows:

Main Plant

Closure of PCAPP’s main plant will be more complicated and take longer than closure of the SDC units, due to its size and complexity. The Chemical Limited Area (CLA) contains multiple rooms and numerous pieces of equipment that will require decontamination, decommissioning and dispositioning before its demolition.

Static Detonation Chamber

Once its mission is complete, the SDC complex will go through the five main steps of closure. As the facility is smaller, less complex than the main plant, and not enclosed in steel-reinforced concrete, the closure process is expected to take less time and manpower. All three SDC units are considered personal property (e.g., end item, material, spares and repair parts), as opposed to real property (e.g., land, buildings, utility systems and other infrastructure), and are being considered for reuse by other governmental organizations.

Property Disposition

Any buildings used directly for chemical agent destruction, such as those in the CLA, will be demolished. Other buildings and infrastructure may be retained by PuebloPlex as real property, as determined by the Base Realignment and Closure (BRAC) plan. Buildings and infrastructure not retained will be demolished as part of the PEO ACWA closure process. As part of the disposition process, personal property, such as uncontaminated or decontaminated equipment, tools, excess parts and office furniture, will be screened for reuse within the Army and other federal organizations prior to being made available to the public as surplus.


Skilled, trained and experienced personnel are the hallmark of the PCAPP project, with many employees having previous destruction and closure experience from other U.S. chemical demilitarization facilities. As the project transitions from operations to closure, the workforce will be reduced as activities conclude within their areas of expertise. To retain these qualified, experienced workers, the government and contractor companies have programs in place to realign personnel with other available positions. Additionally, various government, community and business groups are investigating possibilities for retaining skilled personnel through other local business opportunities. As demolition activities ramp up, the workforce will shift to a commercial contractor focus, with administrative, safety and other positions remaining from operations.

Environmental Compliance

The priority at PCAPP is to ensure the utmost protection to the workforce, community and environment. During closure, PCAPP will continue to operate under local, state and federal laws and regulations. The closure process will principally be governed under a hazardous waste permit issued by the Colorado Department of Public Health and Environment (CDPHE) under RCRA, as well as other applicable environmental regulations and permits administered by the CDPHE and the U.S. Environmental Protection Agency. The end stage of the closure phase for each facility is the closeout of the RCRA and other permits, a major part of the administrative closeout phase.

Public Participation

Another key element of PCAPP closure is the Colorado Chemical Demilitarization Citizens’ Advisory Commission, or CAC. The CAC holds public meetings on a monthly basis. These meetings provide a forum for the PCAPP staff, government officials, PEO ACWA leadership, members of the commission and the public to exchange information regarding chemical weapons destruction and plant closure in Colorado. The CAC will remain active until either the end of closure activities or upon the request of the Colorado governor. At PCAPP, a specific working group meets on a regular basis for citizens to provide input associated with the closure phase.

Partner Organizations

PCD originally stored 2,613 U.S. tons of mustard agent. The mission of PCD is to support delivery of chemical munitions to PCAPP while safely securing, storing and monitoring the chemical weapons stockpile. After PCAPP has completed destruction of the chemical weapons and secondary waste operations in the SDC units, PCD will also go through a closure phase, which includes closing out the igloos that housed the chemical weapons and turning them over to PuebloPlex. The Colorado Chemical Stockpile EmergencyPreparedness Program will close approximately six months after all chemical munitions are destroyed.


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