Title: Use of a resistance meter to monitor groundwater impacts near wastewater holding ponds multi-year summary Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 2, 2014
Publication Date: March 16, 2014
Citation: Eigenberg, R.A., Woodbury, B.L. 2014. Use of a resistance meter to monitor groundwater impacts near wastewater holding ponds multi-year summary [Abstract]. Symposium on Application of Geophysics to Engineering and Environmental Problems (SAGEEP), March 16-20, 2014, Boston, MA. Abstract #54. Technical Abstract: Mineral and organic salts from beef manure that are transported in precipitation runoff from feedyard pen surfaces can alter the conductivity properties of soil and water receiving it. Traditionally, holding pond integrity has been determined using monitoring wells at key locations. However, monitoring wells are expensive to install, costly to sample and the information received is difficult to interpret. Researchers from the USDA-ARS U.S. Meat Animal Research Center have combined efforts and resources with the Nebraska Cattlemen, the Nebraska Department of Environmental Quality, and AgraTek LLC, to evaluate electronic subsurface monitoring of soil quality near runoff holding ponds. This paper summarizes nearly three years of data from two sites. A subsurface resistivity array was installed at a beef cattle feedyard located at the U.S. Meat Animal Research Center, Clay Center, NE (Feedyard A) and at a cooperator site in Central Nebraska (Feedyard B). Array probes were permanently installed at Feedyard A (16 probes spaced 6.1m apart at a depth of 30 cm) and at Feedyard B (32 probes spaced 3.05m apart at a depth of 50 cm). Weekly readings from each site were evaluated to monitor the stability of the zone of hydration near the pond. The low hydraulic conductivity soils at Feedyard A provided in a very quiescent environmental system to evaluate the resistivity array’s inherent measurement stability. The Feedyard B site was typified by coarse textured parent material that had high hydraulic conductivity properties. This site experienced dynamic changes week to week and throughout the season. The resistivity array system was able to adequately measure these dynamics and to alert operators of changes that exceeded nominal operation. This report details geophysical tools that were used to further investigate site B after the permanent array indicated a significant change in subsurface conductivity following a rainfall event.