THE USE OF TRACERS IN SLUG TEST EXPERIMENTS

Despite slug testing being among the most widely utilized methods for determining hydraulic conductivity (K) in the field, there are still uncertainties on the spatial extent of these tests. It is important to determine the extent of slug tests in a given area when planning the number and placement of test wells to be installed. This is particularly vital in regional studies and projects that require high resolution hydrogeological data. This study investigates the potential of using tracers (heat, chloride) and pressure monitoring to determine the spatial extent of slug tests. Both field data from multiple sites and computer models were utilized in this study. Pressure transducers and HOBO thermisters were used to collect water depth, pressure and temperature. MODFLOW and VS2DHI numerical codes were used to model the extent of slug tests. Preliminary results from this study highlight the challenges and difficulties of using tracers for this task. They also show promise and a need for more work in this area. The paper presents lessons learned and discusses future directions of this area of research. Computer models are being calibrated and verified as more field tests are carried out.