In the fall of 2006, Connelly and Associates Inc., one of the largest geotechnical drilling firms in the Washington, D.C., and Baltimore areas, was hired by Schnabel Engineering Inc. to install geotechnical instrumentation and monitoring wells in test boreholes at the Jefferson Memorial. The purpose of the investigation was to determine soil and ground water conditions related to upheaval and movement of the surficial sidewalks, pavement and seawall along the Tidal Basin.