The potential for leakage of injected CO2 at carbon sequestration sites is a significant concern in the design and deployment of long-term carbon sequestration efforts. Effective and reliable monitoring of near-surface environments in the vicinity of these sites is essential to ensure the viability of sequestration activities as well as long-term public and environmental safety. Identification of geologic features (such as faults, fracture zones, and solution enhanced joints that might facilitate release of injected CO2 back into the atmosphere) is a key step in this process. This study reports on near-surface geologic and geophysical characterization efforts conducted at the Department of Energy National Energy Technology Laboratory (NETL) West Pearl Queen carbon sequestration pilot site in southeastern New Mexico, USA, and their use for uncovering possible mechanisms associated with escape of small amounts of perfluorocarbon tracers injected with the CO2.