Residence of the Ambassador of the Republic of Korea

From www.washingtonian.com:

...the American University campus, on a hill overlooking Spring Valley, had been used for producing and testing the most lethal chemical weapons available at the time. Some scientists describe it as the World War I version of the Manhattan Project, which produced the atomic bomb in 1945. After making the weapons on the campus, the Army tested them in the farms and hillsides below. Soldiers tied dogs, goats, and other animals to stakes, set off chemical bombs, and watched the animals struggle and die. Mangled dogs showed up in nearby yards. Soldiers called it Death Valley. Only later, when development began in 1927, did it become Spring Valley.

The Pentagon has a name for old forts and military bases: formerly used defense sites, or FUDS. Spring Valley became the nation's first FUDS with chemical-welfare agents in a residential neighborhood. When the Army Corps of Engineers took over the cleanup shortly after the bombs were found in 1993, it named the task Operation Safe Removal.

Aerial photographs had shown a possible bomb-burial pit along American University's southwest boundary. The Corps had placed it near the Kreeger Building but dismissed it after a cursory search. Albright's 1927 photos showed a pit in the same vicinity, and he asked the Army to look again. The Army realized it had been off by 150 feet. The disposal pit was just across the American University line, which put it in the garden of the South Korean ambassador's residence at 4801 Glenbrook Road.

Even before the Army started excavations in early 1999, ordnance specialists found an empty 75-millimeter shell in the Korean garden. When they looked deeper, they started unearthing bombs, shells, bottles of chemicals, metal drums, and other debris. In July, workers digging in the yard hit soil that started to smoke. It burned for hours. Later that summer two workers were overcome by fumes and taken to the hospital.

After a year of digging, the Army had found more than 623 pieces, including bomb parts and contaminated refuse. Fourteen items still had "chemical-warfare agent," the Army said, but a number of the shells containing mustard gas and arsenic had leaked. Some of the smoke rounds and explosives were intact, with fuses.

Once the bombs and bottles were removed, the Corps told the Koreans it still had to clear the trees, remove at least a two-foot layer of dirt, and replace it with clean soil. The process is ongoing.