Characterization of water infiltration through a municipal solid waste landfill cover vegetated with and without young hybrid poplar trees

Leachate containment at disposal sites in Ontario was not regulated until relatively recently. Poplar tree systems (PTS) are being studied as an alternative landfill cover intended to minimize leachate production on decommissioned sites that lack engineered containment systems. Evaluation includes characterization of water infiltration through the landfill cover before and after PTS establishment.; A dye tracer experiment and horizontal borehole ground penetrating radar (GPR) study characterized soil water infiltration patterns in the upper-most 1.1 m of a 25-year-old decommissioned landfill, with and without a PTS (three-year-old DN hybrid poplar plantation). Digital image analysis characterized the dye infiltration pattern captured with photographs of vertical soil profiles (1 x 1 m). Horizontal cross-borehole GPR measurements taken at 1.1 m depth (2 x 6 m area) characterized changes in soil water content. Results indicate that preferential flow was the primary means of water infiltration with and without the PTS. Direct influences of the PTS were unclear.