In the 1980s, the Army developed binary chemical munitions to replace its aging chemical weapons stockpile. The binary munitions, when fully loaded under battle conditions, consisted of a projectile body and two separate canisters of non-lethal liquid compounds. The two non-lethal liquid compounds, when loaded in the projectile body under battle conditions and fired, would mix, forming chemical agent en route to a designated target. The only binary munition manufactured in quantities beyond research and development levels was the M687 155mm projectile, which formed GB nerve agent. For national security and safety reasons, the Army has always stored the two non-lethal liquid compound canisters in separate locations. Therefore, none of the stored projectiles or canisters contain lethal chemical agents.
The U.S. Army plans to recover and recycle the projectile body and one of the non-lethal liquid compound canisters (designated as the M21 OPA canister). The M687 155mm projectile and the M21 OPA canister are stored at the Deseret Chemical Depot, Utah, and the Umatilla Chemical Depot, Oregon.
The projectile is comprised of a metal body, aluminum explosive casing, and a loaded M21 OPA filled canister. The M21 OPA filled canister contains one of the non-lethal liquid compounds of isopropyl alcohol, or "rubbing alcohol" found in household medicine cabinets, and a related chemical, isopropylamine (the mixture is designated by the acronym OPA).
An international treaty, the Chemical Weapons Convention (CWC), and its supporting agreements, specifically require the disassembly of the M687 155mm projectile and the M21 OPA filled canister. The safe recovery and recycling of the M687 155mm projectile and M21 OPA canister is the responsibility of the Project Manager for Non-Stockpile Chemical Materiel (PM NSCM). The PM NSCM began the disassembly process in November 1997.
The PM NSCM provides for shipment of the M687 155mm projectiles and the M21 OPA filled canisters via a commercial tractor trailer to Hawthorne Army Depot, Nevada. Hawthorne Army Depot, located approximately 140 miles southeast of Carson City, was selected because of its unique capabilities to recover and recycle these various components safely.
The Hawthorne Army Depot recycling and recovery effort consists of three primary steps. First, the M21 OPA filled canister is removed from the projectile, punctured, and drained. The drained OPA liquid is collected in a 55-gallon drum and shipped off site to an approved treatment, storage, and disposal facility for ultimate disposal. The empty canister is shredded and disposed in a regulated, solid waste landfill. Next, an abrasive water jet cuts the metal projectile body in two places to enable removal of the aluminum explosive casing. Once the aluminum explosive casing has been separated, all military markings will be removed to allow for sale of the munition body as scrap metal. Finally, a meltout process removes the explosives from its aluminum explosive casing. Once melted, the explosive is recovered by drying and packaging it for resale and reuse. The empty aluminum casing is smelted into bars and sold for commercial use.
The CWC requires that the United States destroy at least 201,728 of the M687 155mm projectiles within the first two years of the treaty, or by April 29, 1999. Approximately 25 percent of this total was destroyed as of May 10, 1998. To date, the shipment and recycling program has not encountered any safety or security issues.
The remaining binary components are stored at Deseret Chemical Depot in Utah, Umatilla Chemical Depot in Oregon, and Pine Bluff Arsenal in Arkansas. They will be demilitarized in accordance with the CWC by 2007.