Research Capabilities
Subsurface Contaminant Fate and Transport and Risk Assessment Modeling
Contaminants released into the subsurface environment participate in numerous chemical and physical interactions with the inorganic and organic constituents in soil, sediment, and groundwater. The nature of these interactions governs the fate and transport of the contaminants. Computer-based contaminant fate and transport modeling is performed to predict the rate of contaminant migration and to forecast likely future contaminant concentrations at receptor locations. The ultimate objective such an analysis is to evaluate potential future impacts to human health and the environment and to provide a basis for evaluating the effectiveness of proposed remedial alternatives.
Developing a site specific contaminant fate and transport model requires large amounts of input data. Site input data needs include detailed geologic stratigraphy, hydrologic property data, and geochemical data regarding the important interactions that will take place between the contaminants and the geologic components of the surface environment. The geosciences group provides a comprehensive suite of capabilities that can be utilized to characterize site stratigraphy, hydrologic properties, and geochemical properties.
Chemicals released into the subsurface environment are susceptible to chemical reactions that can greatly impact their fate and transport including adsorption, precipitation, dissolution, complexation, hydrolysis, oxidation, reduction, isomerization, biotransformation, and biodegradation. The Geosciences Group has state-of-the-art facilities and laboratories to support mechanistic science-based research to quantify the chemical interactions that occur as contaminants move through the subsurface environment.
Characterization of these complex processes is inherently an interdisciplinary problem. The Geosciences Group is uniquely equipped with the necessary interdisciplinary expertise, facilities, and tools to conduct the required studies to complete these characterization tasks. The Geosciences staff have highly sophisticated experimental and analytical laboratories, modeling capabilities and decision-making tools, which places the Geosciences Group in an exceptional position to conduct detailed investigations for identifying and quantifying the fate and transport of contaminants in the environment.
Several ongoing Geosciences Group projects in this area include: Geochemical Testing and Model Development - Residual Tank Waste, Tank Farm Vadose Zone Studies, 200-BP-5 Operable Unit Conceptual Model Development, and U Geochemistry in waste-weathered Hanford sediments.