Michael N. Fienen

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Knowing the travel-time distributions from infiltrating rivers to pumping wells is important in the management of alluvial aquifers. Commonly, travel-time distributions are determined by releasing a tracer pulse into the river and measuring the breakthrough curve in the wells. As an alternative, one may measure signals of a time-varying natural tracer in(More)
[1] Flow path delineation is a valuable tool for interpreting the subsurface hydrogeochemical environment. Different types of data, such as groundwater flow and transport, inform different aspects of hydrogeologic parameter values (hydraulic conductivity in this case) which, in turn, determine flow paths. This work combines flow and transport information to(More)
A Bayesian inverse method is applied to two electromagnetic flowmeter tests conducted in fractured weathered shale at Oak Ridge National Laboratory. Traditional deconvolution of flowmeter tests is also performed using a deterministic first-difference approach; furthermore, ordinary kriging was applied on the first-difference results to provide an additional(More)
At public beaches, it is now common to mitigate the impact of water-borne pathogens by posting a swimmer's advisory when the concentration of fecal indicator bacteria (FIB) exceeds an action threshold. Since culturing the bacteria delays public notification when dangerous conditions exist, regression models are sometimes used to predict the FIB(More)
To evaluate the potential for in situ bioremediation of U(VI) to sparingly soluble U(IV), we constructed a pilot test facility at Area 3 of the U.S. Department of Energy Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC) in Oak Ridge, TN. The facility is adjacent to the former S-3 Ponds which received trillions of liters of(More)
We characterize the hydraulics of an extraction-injection well pair in arbitrarily oriented regional flow by the recirculation ratio, area, and average residence time in the recirculation zone. Erratic regional flow conditions may compromise the performance of the reactor between a single well pair. We propose an alternative four-well system: two(More)
In situ microbial reduction of soluble U(VI) to sparingly soluble U(IV) was evaluated at the site of the former S-3 Ponds in Area 3 of the U.S. Department of Energy Natural and Accelerated Bioremediation Research Field Research Center, Oak Ridge, TN. After establishing conditions favorable for bioremediation (Wu, et al. Environ. Sci. Technol. 2006, 40,(More)
A field test on in situ subsurface bioremediation of uranium(VI) is underway at the Y-12 National Security Complex in the Oak Ridge Reservation, Oak Ridge, TN. Nitrate has a high concentration at the site, which prevents U(VI) reduction, and thus must be removed. An acidic-flush strategy for nitrate removal was proposed to create a treatment zone with low(More)
Spatially and temporally distributed measurements of processes, such as baseflow at the watershed scale, come at substantial equipment and personnel cost. Research presented here focuses on building a crowdsourced database of inexpensive distributed stream stage measurements. Signs on staff gauges encourage citizen scientists to voluntarily send hydrologic(More)