Publications

The success of engineered remediation is predicated on correct emplacement of either amendments (e.g., vegetable-oil emulsion, lactate, molasses, etc.) or permeable reactive barriers (e.g., vegetable oil, zero-valent iron, etc.) to enhance microbial or geochemical breakdown of contaminants and treat contaminants. Currently, site managers have limited tools to provide information about...

The U.S. Geological Survey (USGS) conducted a series of geophysical investigations to monitor a field-scale biostimulation pilot project at the Anoka County Riverfront Park (ACP), downgradient from the Naval Industrial Reserve Ordnance Plant, in Fridley, Minnesota. The pilot project was undertaken by the U.S. Naval Facilities Engineering Command, Southern Division, for the purpose of...

No abstract available.

Soils and aquifers are major compartments of the subsurface environment, which together control the terrestrial hydrological cycle. This subsurface is important for water resources and also as repository for municipal, industrial, and government waste. Aquifers are typically recharged by natural rainfall entering the soil profile and leaching into deeper soil layers. Due to intensive...

The emerging subdiscipline of hydrogeophysics is underdeveloped in undergraduate curricula relative to its importance in professional engineering/environmental practice. In 2001, the Bucknell Department of Geology initiated efforts to refocus an undergraduate geophysics course on near-surface geophysical methods for hydrologic, environmental, and engineering problems. In addition to...

Direct estimation of groundwater solute concentrations from geophysical tomograms has been only moderately successful because (1) reconstructed tomograms are often highly uncertain and subject to inversion artifacts, (2) the range of subsurface conditions represented in data sets is incomplete because of the paucity of colocated well or core data and aquifer heterogeneity, and (3)...

Two important mechanisms affect our ability to estimate solute concentrations quantitatively from the inversion of field-scale electrical resistivity tomography (ERT) data: (1) the spatially variable physical processes that govern the flow of current as well as the variation of physical properties in space and (2) the overparameterization of inverse models, which requires the imposition...

No abstract available.

Borehole radar tomography was used as part of a pilot study to monitor steam‐enhanced remediation of a fractured limestone contaminated with volatile organic compounds at the former Loring Air Force Base, Maine, USA. Radar tomography data were collected using 100‐MHz electric‐dipole antennae before and during steam injection to evaluate whether cross‐hole radar methods could detect...

An integrated interpretation of field experimental cross-hole radar, tracer, and hydraulic data demonstrates the value of combining time-lapse geophysical monitoring with conventional hydrologic measurements for improved characterization of a fractured-rock aquifer. Time-lapse difference-attenuation radar tomography was conducted during saline tracer experiments at the US Geological...

No abstract available.

The multichannel analysis of surface waves (MASW) seismic method was used to delineate a fault zone and gently dipping sedimentary bedrock at a site overlain by several meters of regolith. Seismic data were collected rapidly and inexpensively using a towed 30-channel land streamer and a rubberband-accelerated weight-drop seismic source. Data processed using the MASW method imaged the...