This project is in the second period of the project. With the tests in three waste and landfill sites, this essay discusses how to efficiently apply geophysical technologies, including electrical resistivity tomography (ERT), ground penetrating radar (GPR) and electromagnetic (EM) method to investigate soil and groundwater contamination. Furthermore, these techniques can test the feasibility of other proven technologies in soil and groundwater applications. This project focuses on detecting the distribution of remediation reagents in the soil and groundwater contamination site. From the ERT results, when the conductivity of remediation reagents is higher than conductivity of groundwater, the rate of increase of the electrical conductivity can estimate the distribution of reagents from time-lapse (TL) analysis. Based on experience, the resolution of surface ERT is common at different depth, so it is suitable for screening evaluation. Comparatively, cross-hole ERT has higher resolution, so it is suitable for surgical remediation design. In the limitations of deep groundwater contamination sites, TL-CHERT is a viable technology, especially for improving the benefits of wells. Besides, multi-frequency EM can detect the conductivity of materials at different depth simultaneously, to increase the effectiveness for investigation at the landfills. Multi-frequency EM is indeed better than traditional single-channel GPR for 3D tomography. However, its skin depth is limited, the accuracy of GPS signal is poor and the funding requirements are high. Apart from this, time domain reflector (TDR) and self-potential method (SP) can detect the reagent transportation, groundwater flow direction and fluid interface etc. these two techniques are still developed. This project also optimizes “Geophysical Exploration Guide”, including the principle and survey process of induction electromagnetic method, case study, ERT numerical simulation, and compiling more than 100 articles of international journals into tables for search.

Soil and Groundwater Pollution, Electrical Resistivity Tomography, Ground Penetrating Radar, EM