Electrical Resistivity Tomography (ERT) is widely used to characterize subsurface structures and to monitor dynamic processes through time-lapse measurements. Its multiscale applicability has enabled laboratory investigations of solute and gas transport in rocks and sediments, as well as field-scale imaging of landfill interiors based on contrasts in moisture content and waste composition. Landfill gas production, primarily CO₂ and CH₄ generated by organic waste degradation, remains difficult to monitor using ERT due to the highly heterogeneous and dynamic nature of waste bodies. To address this challenge, we built a small-scale cylindrical laboratory column, equipped with 64 electrodes to systematically investigate the sensitivity of ERT to gas presence and migration in waste. The experimental setup allows independent control of key parameters including waste grain size, chemistry, saturation, gas volume, flow velocity, and gas composition. This contribution presents the first stage of the project, focusing on the design, optimization, and validation of the ERT column. Using a combination of forward modeling and preliminary laboratory measurements, we assess the system’s spatial resolution, sensitivity distribution, and error sources related to both data acquisition and inversion. The results highlight the importance of pre-optimizing laboratory ERT configurations and provide practical guidelines for the design of similar experimental systems, a step that is often only briefly documented in previous studies.