A fully - automated apparatus for the determination of three types of hy - draulic conductivity

Knowledge of hydraulic properties, such as hydraulic conductivity and soil moisture retention, is crucial for understanding flow and contaminant transport in the subsurface. Hydraulic properties are often important input parameters for numerical simulation of flow and transport. Unfortunately, acquisition of these properties is usually time consuming and costly because of the manual labor associated with the currently available laboratory techniques. Lately, there has been increased interest in automating hydraulic conductivity laboratory techniques to reduce analysis time and improve data consistency. The newly designed fully automated Hydraulic Conductivity Apparatus (HCA), located in the Environmental Molecular Sciences Laboratory at Pacific Northwest National Laboratory, provides enhanced capabilities. The HCA is unique in that it is able to determine hydraulic conductivity with the falling head, constant head, and constant flux methods in a fully automated fashion. This paper demonstrates the new apparatus and presents hydraulic conductivity data for standard laboratory sands. 1 Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory Richland, WA 99352 Tel: (509) 371-6200 e-mail: [email protected] Hydrology Group, Energy and Environment Directorate Pacific Northwest National Laboratory Richland, WA 99352 Tel: (509) 372-6044 e-mail: [email protected] Wietsma, Oostrom, Covert, Queen 2