Unconventional Applications Of Terrain Conductivity Logging To Groundwater Investigations

Conventionally, terrain conductivity logging is used in hydrogeologic studies to map groundwater<br>contaminant plumes of elevated total dissolved solids (TDS). While well-suited to this<br>application, terrain conductivity logging is also a tool useful for approaching a wide variety of<br>other groundwater studies. In this paper, four case studies illustrate the application of borehole<br>electromagnetic (EM) logging to four different problems. The first case study of EM logging iS<br>used to identify fractured zones in an otherwise homogeneous cemented sandstone aquifer. The<br>second case study uses EM logging to establish the connectedness of a fracture or fractures<br>between two monitoring wells. In the third study, multiple aquifers overlooked during drilling are<br>clearly delineated by terrain conductivity logging. In the final study, EM logging is used to<br>describe and delineate paleochannel deposits which are controlling contaminant migration. All<br>of the above studies are related to light non-aqueous phase liquid (LNAPL) remediation projects.