New Model Improves Our Ability to Simulate Contaminant Fate and Transport


Understanding and predicting water flow and contaminant transport at DOE sites is important for developing and monitoring cleanup strategies. Our ability to predict water flow and contaminant transport in unsaturated sediments has been limited by the ability of numerical models to account for the heterogeneity of coarse and fine material layers in those sediments and the scale dependence of hydraulic parameters. A new numerical modeling approach called the Cantor bar model, developed by DOE Office of Science-funded scientists at Oak Ridge National Laboratory (ORNL) and the University of Tennessee, predicts the effective hydraulic parameters of unsaturated flow through thin layers of fine sediment interbedded within a layer of coarse sediments. With additional development, the Cantor bar model should be able to predict the effective hydraulic parameters at various scales. This would be a major step forward in being able to simulate the fate and transport of contaminants at multiple DOE sites. These results were recently published in the Vadose Zone Journal (Tang et al., 7: 493 (2008)).