GEOPHYSICAL ASSESSMENT OF A PROPOSED LANDFILL SITE IN FREDERICKTOWN,MISSOURI

摘要

In June 2018,U.S.Geological Survey in cooperation with the U.S.Environmental Protection Agency(EPA)collected geophysical measurements to help evaluate the suitability of a proposed landfill site for disposing mine-waste materials in Fredericktown,MO.The geophysical investigation included electromagnetic induction,electrical resistivity tomography,horizontal-to-vertical spectral ratio passive seismic,and shear-wave refraction to characterize the unconsolidated sediment or regolith above the bedrock and the depth to crystalline bedrock.Water-based electromagnetic surveys and forward looking infrared imagery were used along the lake shoreline to identify potential groundwater-surface water interactions.Nested piezometers were installed at two locations along the shoreline to further characterize and validate the groundwater-surface water interactions identified with geophysical methods.Collectively,geophysical surveys were used to evaluate the overall suitability of the proposed site for use as a mine waste-soil and sediment repository and to evaluate this suite of geophysical methods for rapid collection and assessment of very shallow sediments.