Implementation of Ground Penetrating Radar in Assessing Leachate in Sanitary Landfill

Leachate accumulation of organic and inorganic contaminants from landfills that disrupt the hydrological system of the soil can cause severe problems for the groundwater table and aquifers. However, it is difficult to predict the presence of leachate produced at the landfill and the heterogeneity of the residual in areas with an in-situ high water table. Consequently, the Ground Penetration Radar (GPR) response was utilized to clarify the in-situ leachate water content. The main objective of this study was to assess the impact of the leachate from the Rimba Mas landfill on a subsurface geological structure by GPR. Leachate migration was detected near the groundwater monitoring station in the Rimba Mas landfill area, Perlis, Malaysia. In this study, a series of measurements for a week was carried out involving shielded antennas with a single frequency, 800Mhz, and 250 MHz GPR on an area of 40m
²
. In addition to GPR signal reflection, an embedded moisture content probe was utilized to identify the consistency of volumetric water content in soil contaminated by waste leachate. Geophysical near-surface processing and interpretation software, particularly ReflexW, was utilized for signal processing for GPR electromagnetic (EM) waves. The comparison of radargrams demonstrated that the 250 MHz frequency yielded more interpretive data, with a reflection coefficient between 20 and 21, and a distinct distinction between the water table and the leachate. The high accuracy at SNR=15.488 and NRMSN=151.942 and NRMSE = 0.216, indicates that GPR can be utilized to assess waste leachate-contaminated areas with a high water table.