The Weldon Spring site first served as the Weldon Spring Ordnance Works, a 17,232-acre World War II plant whose groundbreaking began on Thanksgiving Day, November 28, 1940. It was said to be one of the largest plants of its kind in the world, with a production capacity of 1,080,000 pounds of TNT per day and 40,000 pounds of DNT per day for explosives used in the war effort. The complex had more than 1,038 buildings and reached peak employment of 5,200 people in 1943. By the time production ended on V-J Day, August 15, 1945, it had produced more than 710 million pounds of TNT and 33 million pounds of DNT. In May 1955, about 200 acres of the former ordnance works property were transferred by the U.S. Department of the Army to the Atomic Energy Commission for construction of the Weldon Spring Uranium Feed Materials Plant, later called the Weldon Spring Chemical Plant. From 1957 until 1966, the plant processed uranium ore concentrates and a small amount of thorium. The site then became inactive and deteriorated from 1967 until 1985, when the U.S. Department of Energy proposed cleanup of the area. After passage of the nation's Comprehensive Environmental chemical plant was placed on the Environmental Protection Agency's National Priorities List in 1989. The U.S. Department of Energy then began dismantling the facilities and decontaminating the site, and surface remediation concluded with construction of a disposal cell to hold 1.48 million cubic yards of waste, completed in 2001.
