The Pueblo Chemical Depot is one of the last chemical weapons facilities in the U.S.
Mustard gas is still around. Sulfur mustard, as it is known in scientific fields, is a cytotoxic and vesicant chemical warfare agent that yields the ability to form large blisters on exposed skin and in the lungs. Its uses date back to World War I when the United Kingdom used it against the Red Army in 1919. The most recent recorded use of the chemical weapon was in 2015 when forces of the Islamic State of Iraq and the Levant used the agent against Kurdish forces in Iraq.
How did it get here?
A 1993 chemical weapons treaty signed by the United States and 64 other countries bans the use of mustard gas as a weapon of war. Prior to that, however, Cold War-era strategies and politics led to many of those countries stockpiling millions of tons of the agent in artillery shells.
The treaty led to the disposal of the agent. By the late 90s India, South Korea and Albania had successfully destroyed their stockpiles of the chemical agent. The United States had begun disposing of some of its mustard gas long before the treaty, but the practice of dumping tons of sulfur mustard and other chemical agents into the ocean was put to a halt. By 1972, the United States had dumped 29,000 tons of nerve and mustard agents into the ocean, prompting the U.S. Congress to ban that practice.
Pueblo Chemical Depot
Though the ban slowed the disposal of chemical weapons in the country, it did make room for a more environmentally friendly disposal of the chemical agent. One of the largest stockpile depots was located in northern Utah. The Deseret Chemical Depot began to incinerate its 6,196 tons in 2006 and the last mustard agent artillery shells were incinerated in January 2012. The only two remaining chemical weapons sites are also undergoing a disposal process. One of those is in Richmond, Kentucky, the other is the Pueblo Chemical Depot (PCD) in Pueblo.
The beginning of the end of the Pueblo Chemical Depot began in April of 2015 when three shells were destroyed to inaugurate the multiyear effort to deplete the depot’s stockpiles. The effort is expected to last through 2019.
The initial self-imposed deadline by the country was to have all chemical agents disposed of by 2007. That date was later extended to 2012 and has been extended again while many grapple over what is the safest means of disposal.
A safer process
In September 2016, Pueblo witnessed the destruction of the first chemical agents at the Pueblo Chemical Agent-Destruction Pilot Plant (PCAPP), a state-of-the-art facility built to safely destroy the chemical weapons housed at the PCD. The facility represents a collaborative effort between the Department of Defense’s Assembled Chemical Weapons Alternatives program and the Pueblo community.
The PCAPP uses robotic equipment to remove explosives from the weapon. The system then remotely accesses the weapon’s interior and washes out the mustard agent. The facility neutralizes the mustard agent with caustic solution creating the byproduct hydrolysate. Microbes treat the hydrolysate, breaking it into brine and salt cakes. The cakes are then incinerated and recycled.
Problems at the PCAPP
In December of 2016, the disposal process was halted at the PCAPP due to rainwater that had leaked into the lining of a containment unit. A second incident occurred when 450 gallons of hydrolysate spilled in the plant.
In a press release Sandy Romero, the Communications Manager for the Bechtel Pueblo Team, which manages the PCAPP, said the spill of hydrolysate was not dangerous to Pueblo or any surrounding communities.
Though classified as a hazardous material because it comes from mustard agent, hydrolysate “is basically just salt water,” Romero affirmed.
The disposal process is expected to begin again in 2017, though no clear timeline has been set.