Characterizing the Distribution of Near‐Surface Solution Channels Using Electromagnetic Induction and Ground Penetrating Radar

Abstract

A series of four ponds were developed at a sewage treatment facility in southwestern Oklahoma. Three of these four ponds, when put into service, failed to hold water. The reason for this is that the hydraulic head produced by the water in these ponds caused sink holes to develop into a shallow gypsum formation allowing this water to drain. In order to evaluate potential strategies to mitigate this problem, it was first necessary to establish the horizontal extent and depth interval of the solution channels beneath the sewage treatment ponds. To reach this end, electromagnetic induction (EMI) and ground penetrating radar studies were performed at these ponds. The EMI data showed a distribution of apparent low electrical conductivity regions that correlated well with the pattern of open sink holes. Two‐ and three‐dimensional images reconstructed from the GPR data provided confirmation of the EMI results and established a depth to the voids of about 40 cm.