High-Frequency Acoustic Imaging Of L Lake, Savannah River Site, South Carolina

A side scan sonar and seismic reflection study of L Lake, Savannah River Site, South<br>Carolina, was performed in June 1996. The geophysical investigation was conducted to<br>determine the location, distribution, and depth of existing burial pits and mounds within the<br>reservoir for incorporation into an Environmental Impact Statement. The results are also<br>intended to supplement previous scientific information obtained from soil samples, aerial<br>photography, and radiometric studies. Interpretation of the sonar data revealed numerous<br>mounds along the reservoir bottom that appear to have been constructed by pushing nearby<br>material into a heap to cover either the contaminated vegetative material, its ashes, or<br>contaminated sediments. The mounds do not cover any burial trenches or pits although some<br>small depressions are detected underneath the mounded material.