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former Administrator of the National Nuclear Security Administration
March 7, 2018
Beyond the Chemical Weapons Stockpile: The Challenge of Non-Stockpile Materiel

June/July 1998

By Milton E. Blackwood, Jr.

In 1985, Congress passed legislation requiring the U.S. Army to dispose of its stockpile of unitary chemical warfare (CW) agents and munitions, comprising over 3 million weapons containing roughly 12,000 tons of agents and another 19,000 tons of chemicals in bulk storage.(1) Recognizing that the stockpile did not represent the entirety of U.S. CW materiel, Congress in 1992 also ordered the Army to dispose of chemical materiel not part of the stockpile. This "non-stockpile" materiel includes buried chemical materiel, binary chemical weapons, recovered chemical weapons, former chemical weapons production facilities, recovered chemical weapons and other miscellaneous chemical warfare materiel. The United States further demonstrated its commitment to abandon its CW capabilities on April 24, 1997, when the Senate, by a vote of 74-26, gave its advice and consent for the ratification of the Chemical Weapons Convention (CWC). The United States became an original state-party to the CWC five days later when the convention entered into force.

The CWC not only prohibits the use, production, acquisition and transfer of chemical weapons, but also requires states-parties to destroy their existing weapons and production facilities. By ratifying the treaty, the United States agreed to dispose of its most dangerous CW holdings—its unitary and binary chemical weapons, recovered chemical weapons and chemical weapons production facilities—by April 29, 2007. In addition, the United States agreed to dispose of all other CW-related materiel (for example, chemicals and precursor agents that pose a lesser risk to the purposes and objectives of the treaty but that may be produced commercially) by April 29, 2002.(2) Although the CWC does not stipulate the means of destruction to be utilized, it prohibits disposal by dumping into a body of water, land burial or open-pit burning, and requires that the chosen technology destroy the chemical agent in an irreversible manner that also protects the safety of humans and the environment.

The Army originally planned to build incineration facilities at each stockpile storage site to carry out on-site disposal of this chemical materiel. This strategy has met strong objections from environmental groups and concerned citizens, who question the safety of incineration. These objections have delayed the construction of disposal facilities and have motivated Congress to require the Army to research alternative disposal technologies to incineration. Since 1985, the Army's cost estimate for the stockpile disposal program has increased from $1.7 billion to $15.7 billion, and its projected completion date has slipped from 1994 to 2007.(3)

While public attention has largely focused on the Army's stockpile disposal program, several accidental discoveries of chemical munitions on civilian-owned sites have increased interest in the non-stockpile program. The non-stockpile disposal program is currently projected to cost $15.1 billion—nearly the cost of the stockpile disposal program—and will take well into the next century.(4) Addressing the problem of buried CW materiel is, by far, the biggest challenge for the non-stockpile disposal program. The Army estimates that it will take until 2033 to complete and require 95 percent of the program's budget to identify, recover and dispose of all buried chemical materiel.(5)

The CWC does not necessarily require the disposal of buried chemical warfare materiel. According to Article III.2: "The provisions of [the treaty] shall not, at the discretion of a State Party, apply to chemical weapons buried on its territory before 1 January 1977 and which remain buried…." However, if a party decides to recover buried materiel, the materiel is then subject to the requirements of the CWC. Thus, if the United States decides to allow this materiel to "remain buried," it will be released from declaring the chemical materiel burial locations to the Organization for the Prohibition of Chemical Weapons (OPCW)—the implementing body established by the convention—and from the requirement to dispose of the munitions.

The U.S. Stockpile

The remaining U.S. stockpile of some 28,000 tons—mostly mustard gases and the nerve agents VX, GB (Sarin) and GA (Tabun)—is stored at eight sites in the continental United States and on Johnston Island in the Pacific Ocean.(6) The chemical agents exist in a variety of containers (aerial spray tanks and bulk containers) and munitions (bombs, landmines, rockets, artillery projectiles and mortar projectiles), complicating their disposal. Many of the munitions have associated explosives or propellants (known collectively as energetics), which also make disposal more difficult.

The poor condition of the stockpile was a major factor in Congress's decision to order its destruction. All of the chemical agents and munitions were produced prior to 1969, and many are now more than 50 years old. Between 1982 and 1992, the Army reported nearly 1,500 leaking munitions, and in 1993 a 100-gallon spill of a mustard agent from a bulk container was found at the Tooele Army Depot in Utah. The stability of thousands of M-55 rockets loaded with chemical agents is of particular concern.(7) Under certain conditions, the propellant in the M-55 rockets can break down in a manner that could lead to autoignition. The Army believes that the stockpile—including the M-55 rockets—should be stable until its disposal is complete, and will continue to monitor the stockpile closely until it is destroyed.


Buried Chemical Weapons

A greater variety of chemical agents is present in the non-stockpile materiel, with identified agents including blister agents (mustards and lewisite); nerve agents (GA, GB and VX); blood agents (hydrogen cyanide and cyanogen chloride); and a choking agent (phosgene). In addition, the condition of the non-stockpile materiel is far more variable than that of the stockpile materiel and much is still unknown about the amounts and conditions of chemical materiel that is currently buried. Until the late 1950s, burial was considered to be a final disposal solution for obsolete chemical weapons, and thorough record keeping of this activity was rare.

Even at sites where chemical weapons are known to be buried, the amounts, types and conditions of the agents are often unknown. Deterioration also has obscured identifying markers on many of the buried weapons recovered.

Accidental discoveries of CW materiel by the public have demonstrated the seriousness of the buried weapons problem. In 1995, workers found a chlorine-filled projectile at Fort Lewis in Washington, DC, during construction of a housing development, and contractors digging utility lines at the Mississippi State Fairgrounds in Jackson uncovered glass vials containing chemical agents. Eventually, more than 260 vials containing phosgene, mustard and lewisite were found at the site (near a former National Guard armory), which was only a few blocks from the state capitol.

Fortunately, by the time the United States acquired large amounts of the most deadly CW materiel—nerve agents—burial was a less common choice for disposal, and most chemical materiel recovered so far under non-stockpile programs has been either World War I-vintage mustard agents or agents now considered legitimate industrial chemicals.(8) While recovered chemical weapons do include some nerve agents, these are more likely to be found at military sites such as firing ranges rather than in areas with significant public access.

Buried chemical weapons do represent a safety risk for the public. Agents disposed in closed containers (like much of the buried material discovered thus far) can remain active for many years. Between 1985 and 1995, for example, Dutch fishermen reported more than 350 cases where chemical weapons, dumped into the Baltic Sea after World War II, were caught in fishing nets, some resulting in serious burns.(9) In 1996, China reported that more than 3,000 injuries had resulted from chemical weapons left in that country by Japan during World War II.(10)

Where chemical agents have leaked out of their containers or were simply poured into the ground and covered, the condition of the agent is unknown because degradation of chemical agents in soil is a complex physical process affected by a variety of factors such as the type of agent; soil composition and properties (acidity, alkalinity, temperature, moisture content and ion content); meteorological conditions; and types of organisms present in the soil.(11) The most persistent agents—sulfur mustards—can remain dangerous for decades. Sulfur mustard dumped in 1941 at the Aberdeen Proving Ground in Edgewood, Maryland, could still be detected in the soil 30 years later.(12)

The Army has identified 224 potential burial sites at 96 locations in 38 states, the District of Columbia and the Virgin Islands.(13)(See Figure 1.) Of the 96 locations, 45 are on former defense sites and 51 are on current Department of Defense installations. The former military sites are now under private ownership or under the control of other governmental agencies. Of the 224 potential sites, the Army believes that 56 require no further action. (Once a potential site is identified by the Army, for safety reasons that site remains on the Army's list indefinitely.) In addition, potential overseas chemical weapons burial sites have been identified, but their locations are classified. Under the CWC, a state-party that has abandoned chemical weapons on the territory of another state-party has the responsibility for their removal and disposal.

In contrast to buried chemical weapons, the Army has better information about the four other categories of non-stockpile materiel. Much of this materiel has been located and inventoried at various sites across the United States. Given the diversity and the differing states of deterioration of this materiel, its destruction will present challenges for the Army.


Binary Chemical Weapons

Binary weapons were developed in the 1980s to replace the aging stockpile of unitary chemical weapons. For safety and security reasons, binary weapons were constructed, stored and transported with one of the non-lethal agents within the munition, and the other non-lethal agent produced, stored and transported separately. The second agent was only to be loaded into the munition on the battlefield prior to delivery.

Three binary weapons systems—Multiple Launch Rocket System (MLRS) munitions, "Bigeye" gravity bombs and artillery projectiles—were tested or developed by the U.S. military. The MLRS munitions never reached full-scale development and the prototype production facilities and equipment are currently either in layaway status or storage, and have been inspected by the OPCW. The Navy-developed Bigeye used a liquid precursor (QL) and sulfur powder to form the nerve agent VX. The Bigeye was designed to mix the two agents after release from an aircraft and spray VX over the intended target area. Two hundred test weapons were produced prior to termination of the project. The M-687 155-millimeter binary artillery projectile was the only binary weapon to reach the full-scale production. The projectile utilized a liquid precursor (DF) and a non-lethal compound (OPA) to form the nerve agent GB.

Recovered Chemical Weapons

Chemical weapons retrieved from range-clearing operations, research and test sites, and burial sites are classified as recovered chemical weapons. The amount of chemical agents in this non-stockpile materiel comprises only a fraction of the total of stockpile agents. All the materiel recovered thus far contains only hundreds of tons of agent and could, in theory, be placed in a single 25 foot-by-80 foot storage building.(14) This amount will grow as more materiel is recovered from burial sites, but the Army does not expect this total to greatly increase. This, of course, does not mean that the disposal of the materiel is simple. Not only are many more sites involved but much of the non-stockpile materiel is quite deteriorated and contains unidentified chemical agents that greatly complicate its disposal.

Of the more than 7,000 items recovered to date, 1,692 are chemical munitions and more than 5,404 are Chemical Agent Identification Sets (CAIS) or CAIS components. From 1928 until 1969, approximately 110,000 CAIS were produced and distributed to train both military personnel and civilians (for example, air wardens during World War II) in the safe handling, identification and decontamination of CW agents. The sets consist of ampules, vials and bottles of chemical agents packed into metal or wooden containers. Because the CAIS are training items for defense against a chemical attack, the CWC does not require their disposal. However, the congressional order requires the Army to dispose of all recovered CAIS. In the 1980s, the Army destroyed approximately 21,000 CAIS, but the missing sets are of particular concern because several have been discovered off military sites by private citizens, including the discovery at the Mississippi State Fairgrounds.


Former Production Facilities

The CWC requires the declaration and destruction of all former chemical weapons production facilities constructed or used after January 1, 1946. The United States has declared 13 former production facilities in seven states (one facility each in Alabama, California, Indiana, Maryland and North Carolina, and four facilities in both Arkansas and Colorado). The OPCW can grant permission to convert these facilities to non-prohibited purposes if a state-party can prove a compelling need for such action.


Miscellaneous CW Materiel

Miscellaneous CW materiel includes:


  • Items designed specifically for conducting chemical warfare, such as unfilled munitions, empty rocket warheads, fuzes and bursters designed for chemical munitions, and simulant-filled munitions;


  • Chemical samples transferred from suspect containers into safer storage devices;


  • Ton containers in which chemical warfare agents were previously stored or shipped; and


  • Research, development, test and evaluation (RDT&E) chemical warfare materiel, which are items used for the development of chemical weapons.


The CWC requires disposal of the first two groups of miscellaneous materiel. The ton containers are not controlled by the CWC because they are used to store commercial chemicals as well as CW agents. While the Army currently lists no items in the RDT&E group, it may reclassify some chemical sample materiel as RDT&E for future chemical defense research allowed by the CWC.


The Challenge of Disposal

The Army's Non-Stockpile Chemical Materiel Program (NSCMP) was established in 1992 to dispose of non-stockpile materiel. Rather than relying on accidental discoveries of non-stockpile materiel, the Army is actively seeking to locate any and all potential chemical materiel burial sites. This effort has involved extensive review of historical documents, visits and examinations of potential sites, and interviews with personnel who may have knowledge of burial activities.

When a potential burial site is identified, often an archaeological-type excavation must be used to avoid possible accidental release of agents or detonation of a munition's energetics. Metal detectors can also be used to detect potential buried chemical weapons containers and munitions. However, almost any site that has ever been used by humans for any purpose will contain some metal waste, so these instruments are of limited use in confirming the presence of buried munitions. When a burial site is confirmed, a decision has to be made whether excavation and destruction pose less risk to health and environmental safety than leaving the weapons in the ground.

Dealing with the four categories of non-stockpile materiel besides buried chemical materiel is projected to require only 5 percent of the total non-stockpile budget of roughly $15 billion. Also, the estimates for the time required for their disposal—10 years each for binary munitions, former production facilities and recovered chemical weapons, and five years for miscellaneous CW materiel—are much shorter than for buried weapons and would meet the deadlines of the CWC.

In November 1997, the Army began shipping the first of 201,728 M-687 artillery projectiles stored at Umatilla Chemical Depot in Oregon to Hawthorne Army Depot in Nevada for destruction and recycling. At the Nevada facility, the canister containing the chemical compound is removed and the agents drained so the compound can be shipped and disposed of elsewhere. Following disassembly, the metal projectile body and aluminum explosive casing, once processed, are sold commercially and the explosive is recovered for reuse. As of late July, more than half of the weapons had been eliminated, a process the Army estimates will be completed by April 1999. The second binary component of the M-687 (DF) is stored separately and can be destroyed by commercial disposal facilities. In addition, the Army has nearly completed destruction of all the remaining components of Bigeye bombs at Pine Bluff Arsenal in Arkansas.

Although all former chemical weapons production facilities are considered non-stockpile materiel, the NSCMP is currently responsible for demolishing only those facilities in Arkansas, Indiana and Maryland. Efforts to destroy a former VX production facility in Newport, Indiana, and a pilot plant at Aberdeen Proving Ground in Maryland began in 1998. The facilities in Colorado's Rocky Mountain Arsenal are being dealt with by a separate Army program manager and the Tennessee Valley Authority is responsible for the Alabama site. Decisions for the California and North Carolina facilities are still pending. According to the U.S. On-Site Inspection Agency, all facilities are closed down except the Marquardt Company in California, which has been converted to peaceful purposes.

Miscellaneous CW materiel is also being destroyed. More than 8,000 unfilled chemical weapons projectile bodies have been destroyed at Deseret Chemical Depot in Utah. Some 1,600 ton containers that were previously used to store bulk amounts of chemical agents have been recycled and another 5,400 will be recycled. The containers, which are made of high-grade steel, are checked to make sure they are not contaminated and then cut in two and cleaned before shipment to Rock Island Arsenal in Illinois, where the halves are smelted into steel ingots. Because most of the containers predate World War II, their steel is radiologically very pure and very valuable for construction of such things as Geiger counters.


Disposal to Go

Because the unitary chemical agents contained in buried and recovered munitions and miscellaneous CW materiel can only be destroyed by special facilities, and because of the problems that would be associated with transporting such agents, the Army plans to analyze and destroy this materiel on-site whenever possible. The Army therefore is currently developing a number of mobile disposal units that are capable of traveling to individual non-stockpile sites. These mobile tools include the Mobile Munitions Assessment System (MMAS), Munition Management Devices (MMDs), and the Rapid Response System (RRS).

The MMAS was developed for the rapid assessment of the contents of recovered chemical weapons and can be transported to any site in the country (it can be carried by C-130 transports). The MMAS contains three X-ray devices for analyzing the condition of any explosive present and a portable isotopic neutron spectroscopic system to establish the identity of any chemical agent present. Communication devices (satellite up-links, cellular phones and short-wave radios) and imaging systems allow the MMAS crew to stay in contact with experts and decision-makers from remote locations. Additionally, weather monitoring devices allow the determination of climatic conditions that could affect disposal activities.

The disposal systems of these mobile facilities utilize chemical neutralization with strong bases and bleaches to destroy the CW agents. The resulting solutions can be sent to a commercial hazardous waste facility for final disposal. MMDs are designed for on-site treatment of non-explosive bombs and recovered artillery projectiles. The RRS is designed to access, neutralize and containerize treated waste from recovered CAIS. The CW agents will be processed by the RRS, while other chemicals contained in the CAIS, now classified as industrial chemicals, will be repackaged and transported to industrial disposal sites.

Before any of the Army's mobile devices for destroying non-stockpile materiel can be used, the Army must demonstrate that they meet all state and federal laws and regulations. The NSCMP expects to receive a permit to use its RRS system in Utah by the end of the year. Recently, researchers at Sandia National Laboratories demonstrated that the Army's mobile destruction facilities could completely and safely destroy the CW agent phosgene. Besides inspecting potential non-stockpile sites and developing technologies for destroying chemical materiel when discovered, the NSCMP is also making a concerted effort to educate local citizens and officials of the risks at non-stockpile sites and how to safely treat newly discovered materiel before the Army responds.

Because some non-stockpile sites are colocated with stockpile storage sites, it could be argued that stockpile disposal facilities at these sites should also be used to destroy the non-stockpile materiel. However, to reduce public fear that permanent chemical waste disposal facilities would be located in their vicinities, Congress mandated that the stockpile disposal facilities can destroy stockpile agents only and must be demolished after they destroy the stockpile materiel at a site. Currently, the Army is making no effort to change this law. It is worth noting that the variety and poor condition of much of the non-stockpile materiel likely mean that stockpile facilities could not be used to destroy all non-stockpile materiel, even if it were allowed by law.

Uncertainties Remain

In 1997, the General Accounting Office (GAO) predicted that, as has happened to the stockpile disposal program, the cost and time requirements of the non-stockpile disposal program could also surpass existing estimates.(15) The GAO stated that uncertainties about buried chemical weapons, unproven destruction technologies and expected difficulties in obtaining the needed environmental permits and approvals will likely affect the Army's non-stockpile disposal efforts. Having spent only $280 million of its expected $15.1 billion budget and with the program's expected completion date still decades away, the NSCMP has an uncertain future.

Possibly the biggest problem for the Army will not be technical in nature but political. The Army must convince the public that it can carry out the non-stockpile disposal program in a safe manner. One need only examine the controversies surrounding the disposal of stockpile agents and of Iraqi chemical weapons in the aftermath of the Gulf War to realize this will not be a simple task. While the Army's focus on mobile disposal systems is a promising development, the Navy's recent difficulty in trying to transport napalm from California to Indiana for recycling clearly demonstrates the public's objection to moving military chemicals around.(16) Public opposition to transporting more lethal CW agents will likely be even stronger.

The Army's non-stockpile CW disposal program demonstrates how past poor decisions on waste disposal can lead to future environmental problems and huge monetary costs. The decision to bury chemical weapons was considered to be a final disposal solution, but it is turning out not to be final at all. As the country must continually seek safe ways for disposing dangerous materiels, whether they are CW agents, spent nuclear fuel or industrial waste, it must remain aware that decisions made today will have far-reaching and serious consequences for the future.



1. Binary munitions contain two, separated non-lethal chemicals that react to produce a lethal chemical when mixed during battlefield delivery. Unitary weapons, most of which are in the stockpile, contain a single lethal chemical in a munition. Other unitary agents are stored in bulk containers. [Back]

2. The Executive Council of the Organization for the Prohibition of Chemical Weapons (OPCW), the international forum that oversees treaty implementation and compliance, can grant up to a five-year extension to these dates on a one-time basis. [Back]

3. Office of Program Manager for Chemical Demilitarization. [Back]

4.Chemical Weapons and Materiel: Key Factors Affecting Disposal Costs and Schedule, General Accounting Office (GAO), GAO/NSIAD-97-18, February 1997, p. 40. [Back]

5.Ibid. , p. 40. [Back]

6. Stockpile storage sites are located in Alabama, Arkansas, Colorado, Indiana, Kentucky, Maryland, Oregon and Utah. For a more complete description of the U.S. stockpile, see: Recommendations for the Disposal of Chemical Agents and Munitions, National Research Council, 1994, Chapter 2. [Back]

7.Chemical Weapons: Stability of the U.S. Stockpile, GAO, GAO/NSIAD-95-67, December 1994. [Back]

8. Author interview with Colonel Edmund W. Libby, project manager for U.S. Army Non-Stockpile Chemical Materiel Project, August 1998. [Back]

9.Conversion Survey 1997, Bonn International Center for Conversion, Chapter 4. [Back]

10. "Japanese Chemical Weapons Threaten Lives in China," Xinhua News Agency, January 13, 1996. [Back]

11. Ralf Trapp, The Detoxification and Natural Degradation of Chemical Warfare Agents, Taylor & Francis, London, published for the Stockholm International Peace Research Institute (SIPRI), 1985. [Back]

12.The Challenges of Old Chemical Munitions and Toxic Armament Wastes, T. Stock and K. Lohs, eds., Oxford University Press, Oxford, published for SIPRI, 1997, Chapter 11. [Back]

13.Op. cit., Libby interview. [Back]

14.Op. cit., Libby interview. [Back]

15.Op. cit., GAO/NSIAD-97-18, p. 40. [Back]

16. Eric Lichtblau, "Napalm Train Now on a Road to Nowhere," The Los Angeles Times, April 17, 1998, p. 1. [Back]


Milton E. Blackwood, Jr. is a post doctoral associate with the Peace Studies Program at Cornell University.