This high-resolution 3-D seismic reflection experiment was designed to map the geometry of a buried paleo-channel in the contest of groundwater remediation. The channel is eroded in clay and acts as a trap for polluting dense non-aqueous phase liquids. The seismic data were acquired using more than 600 REF TEK 125A single channel seismic recorders with 40 Hz geophones. The area of interest is approximately 40x90 meters and the target is at 10-15 meters of depth.