ERT Monitoring Of Recycled Water Injection In A Confined Aquifer

This work describes the installation and measurements of an electrical resistivity tomography (ERT) system to monitor the injection of recycled water into a confined aquifer in the area of Sindos (Thessaloniki, N. Greece). The aim is to provide, through time-lapse ERT measurements and processing, geoelectrical images of rather increased volumetric sampling around and between the holes and to obtain improved understanding of the flow and transport of the injected water. The details about the general setting, the construction and installation of the ERT cables into the boreholes are explained in full. Measurements involving single and cross-hole ERT measurements in time-lapse mode were obtained and processed with a 2D inversion algorithm to produce images of the subsurface. Results depict a very good correlation between ERT images and the lithology and resistivity logs an indication of the reliability of the approach.