Water Resources Research Act Program

Details for Project ID 2004ID25B

Advanced Cone Penetrometer Technology for In-Situ Measurement of Unsaturated Soil Hydraulic Properties

Institute: Idaho
Year Established: 2004 Start Date: 2004-03-01 End Date: 2005-02-28
Total Federal Funds: $15,000 Total Non-Federal Funds: $39,238

Principal Investigators: Molly Gribb

Project Summary: Protection of groundwater resources is an issue of critical importance in Idaho and across the nation. Areas where groundwater is shallow and/or overlain by permeable materials are especially susceptible to contamination. To predict the fate and transport of contaminants as they travel through the unsaturated zone to the groundwater below, hydrologic modelers need accurate values for soil hydraulic properties. Unfortunately, conventional field test methods for determining the hydraulic properties of unsaturated soils are commonly limited in depth of application, and can be time consuming and labor intensive. Laboratory methods have the added disadvantage of requiring removal and handling of potentially contaminated soil. In many cases, laboratory tests do not adequately reflect the in-situ behavior of the soil, due to the small sample size and/or disturbance of the soil structure that occurs during sampling. In noncohesive soils, it is often very difficult, if not impossible, to obtain undisturbed samples. To address limitations of existing field methods, a new cone penetrometer tool, called a cone permeameter, and an inverse solution approach have been developed and successfully tested under laboratory and field conditions. In this project we seek to capitalize on past research successes and advance the state of the art for extracting detailed hydraulic information about unsaturated, as well as saturated soils, from transient field data. Project activities will include a series of experiments to calibrate and validate a new prototype cone permeameter. The prototype will be calibrated in a controlled setting in the laboratory and then tested in a fully instrumented soil test bed. The training objective of the Water Resources Act of 1984 will be met as a civil engineering masters student will be supported on this project and gain unsaturated soils research experience.