During World War I, American University allowed the United States Army to use part of its campus for weapons development and testing.

What is now Spring Valley was an undeveloped area on campus where the Army was allowed to use for testing chemical weapons, such as mustard gas.

[2] The next day it was reported in The Washington Post that World War I bomb shells had been unearthed near a senator's house bordering the campus.

This touched off a cleanup effort by the Environmental Protection Agency and the Corps of Engineers who called it the Spring Valley Formerly Used Defense Site.

[3] In 2003 many more dangerous sites in the area were uncovered, including perchlorate in groundwater and three burial pits on grounds of the South Korean ambassador's residence.