SAVANNAH, Ga. — A well drilling rig used by the U.S. Army Corps of Engineers Savannah District's subsurface exploration unit. The U.S. Army Corps of Engineers Savannah District hosted 82 engineers, geologists, drillers, and other professionals from locations across USACE for the Joint Conference of the Geology and Geotechnical Communities of Practice, Aug. 14-16, 2012.