Preliminary Determination of Pollutants Plume in Groundwater at Hazardous Solid Waste Disposal Site by Employing CPT and Rig

Abstract

This study was conducted to delineate a plume occurred in hazardous waste disposal site in Brisbane, Australia. At first, levels of conductivity observed during Cone Penetrometer Test (CPT) loggings were initially indicative that possible contaminants are depth-variably presented with showing the highest at approximately 200 mS cm−1 in 9 m deep from some of locations. Subsequently, CPT rig and HydroPunch were used to collect depth-discrete groundwater samples in the area where CPT loggings had been undertaken. However, it was not capable of sampling the representative groundwater samples due to the cone refusal where the residual clay is layered at nominal depth through the aquifer. Alternatively, a number of temporary wells were installed after each of locations was penetrated using a modified steel cone functioned by CPT rig. The samples taken from those of wells were characterized by gas chromatography mass spectrometer (GCMS) and gas chromatography filame ionization detector (GCFID), which revealed that sulfolane and thiolane were mainly presented. Subsequent analyses performed for the samples taken from permanent nest piezometers consistently demonstrated that possible plume boundary would be correspondingly presented in the study area where contaminants were found as low as detection limit or levels of not-detectable.