The unit also manages U.S. Department of Defense contracts to dismantle and dispose of stored chemical weapons, including decades-old mustard and nerve gas from World War II.[1][2][3] By 2019, the Pueblo Chemical Agent-Destruction Pilot Plant in Colorado had destroyed nearly 100,000 munitions.[190] Bechtel completed the construction of the Blue Grass Chemical Agent-Destruction Pilot Plant in 2015.[191] Since May 2012, Bechtel has been part of a consortium completing the Chernobyl New Safe Confinement, a structure that will safely confine the damaged Chernobyl Nuclear Reactor Number 4.[192] Bechtel continues to oversee the operation.