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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Nutrition, Growth and Physiology » Research » Publications at this Location » Publication #304515
Title: Resistivity arrays as an early-warning system for monitoring runoff holding ponds

Author
item Woodbury, Bryan
item Eigenberg, Roger
item FRANZ, TRENTON - University Of Nebraska

Submitted to: Journal of Environmental & Engineering Geophysics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/25/2015
Publication Date: 12/2/2015
Citation: Woodbury, B.L., Eigenberg, R.A., Franz, T.E. 2015. Resistivity arrays as an early-warning system for monitoring runoff holding ponds. Journal of Environmental & Engineering Geophysics. 20(4):319-335. doi: 10.2113/JEEG20.4.319.

Interpretive Summary: Monitoring wells are installed downstream from feedlot runoff holding ponds to determine if they are leaking contaminants to groundwater. For many reasons, these wells are not effective for monitoring contaminant leakage. The objective of this study was to evaluate the effectiveness of a new method for monitoring contaminant leakage from runoff holding ponds. This method used a series of probes that were placed in the ground near the surface. These probes allowed a virtual curtain to be created next to the pond so that if any contaminant leaked out of the pond it would be measured immediately. The new method responded quickly to leakage from a holding pond. The new method can be automated so that ponds can be continuously monitored. The automation can send alerts by email or text messages to managers if a leakage is detected. This alert system allows managers to take corrective actions much quicker than traditional monitoring wells. This quick action limits harm to the environment.

Technical Abstract: Monitoring wells are installed to intercept contaminants inadvertently discharged from in-ground structures designed to retain salt-affected wastewaters; however, several difficulties with collection and data interpretation limit their effectiveness. Therefore, improved monitoring methods are needed. The objective of this study was to evaluate the effectiveness of resistivity array technology as an early warning system to monitor for unintended basin discharge. Subsurface resistivity arrays were installed at two Nebraska sites: a beef cattle feedyard located at the U.S Meat Animal Research Center, Clay Center (FyA) and a commercial cattle feeding operation (FyB). Monitoring well data did not identify any unintended discharge events during the study period. However, the resistivity array system (RA) detected a discharge event that was localized in the non-saturated zone adjacent to the pond at FyB within one day following a precipitation event. Monitoring the unsaturated portion allows the RA system a capacity beyond traditional monitoring wells which can only intercept discharge carried in groundwater. Also, the RA system effectively measured a larger area (a virtual curtain) compared to the point measure typical of monitoring wells. Therefore, RA technology provides broader coverage and is more tolerant to placement issues for intercepting discharge. Finally, the capacity to automate the RA system provides a means to continuously monitor unintended subsurface discharge from runoff holding ponds. This continuous monitoring system is much more likely to detect discharge events than the bi-annual sampling typically required for monitoring wells. Automatic and continuous monitoring provides feedyard operators’ options to better manage environmental impacts associated with runoff holding ponds.