Monitoring Transport of Contaminants During Snowmelt Infiltration with Invasive and Non-invasive Techniques

The impact of agriculture, industry, airport activities on soil and water quality is strongly influenced by soil heterogeneity. At Oslo airport large amounts of de-icing chemicals are used for removal of snow and ice. The objective is to quantify how the different processes occurring during snowmelt infiltration of meltwater contaminated with de-icing chemicals affects the geophysical signals. The study describes two field experiments were tensiometers, suction cups, and multi- compartment sampler (MCS) techniques have been combined with non-invasive time-lapse electrical resistivity measurements (ERT). The MCS combines variable-suction with multi-compartment aspects to measure spatial and temporal distribution of water flow and solute transport. The tracer experiments were performed at the research station at Oslo airport. The low resistivity values at the top of the ERT profiles on day 6 and 12 are explained by rapid increase of water saturation (Day 6), derived from tensiometer data, and infiltration of tracer (Day 12), derived from suction cup data. The low resistivity is also explained with MCS by saturation conditions at day 3 and increased electrical conductivity at day 12. By combining ERT, tensiometers, water sampling via suction cups or MCS, we can observe the contributions from water content and solute concentration to ERT.