By Rebecca Blatt
The U.S. Army Corps of Engineers has uncovered what could be a fourth major disposal area for World War I-era munitions near American University in D.C.
Project Manager Dan Noble says workers pulled smoking glassware from the dig site in Spring Valley. Preliminary tests show it was contaminated with the toxic chemical arsenic trichloride.
Noble says this is the first discovery of the chemical in the Spring Valley project. But during World War I, the Army used the university to develop and test chemical weapons.
Dozens of other items also have been uncovered in recent months, including a jar of the chemical agent mustard.