Sod staples and nails unearthed by U.S. Army Corps of Engineers contractors during a munitions investigation at a private property at the Spring Valley Formerly Used Defense Site in Washington, D.C., Dec. 1, 2009. "False digs" of cultural debris like this are common when looking for potentially buried munitions, and the U.S. Army Corps of Engineers is currently using the latest Advanced Geophysical Classification technology in Spring Valley to reduce the number of false digs during ongoing munitions investigations work.