Assessment of groundwater contamination by landfill leachate with ground penetrating radar

Abstract

This study was conducted to identify field scale groundwater (GW) contamination by the leachate generated due to an open dump site using ground penetrating radar (GPR) and to study the GPR wave response under different contaminant levels using GprMax2D. An area of 30 m × 30 m was selected near to the Gohagoda open dump site in Kandy, Sri Lanka (7° 18'N and 80° 37'E). Ten GW monitoring wells were installed. In the GPR modeling, a model domain of 4.0 m × 3.0 m with four different layers was used. The average EC value of raw leachate, soil extraction and GW were 0.6, 0.01 and 0.09 S/m, respectively. A leachate layer with an EC value similar to GW was used in GPR modeling. Results revealed that when a leachate having an EC value of 0.09 S/m, sub-surface reflections below the GW table dissapere. The GPR technique can be used for identifying contaminated plumes in GW due to landfill leachate.