THE BC CRIBS & TRENCHES GEOPHYSICAL CHARACTERIZATION PROJECT ONE STEP FORWARD IN HANFORDS CLEANUP PROCESS

Abstract

INFORMATION CLEARANCE FORMT h e BC C r i b s and T r e n c h e s G e o p h y s i c a l C h a r a c t e r i z a t i o n P r o j e c t :One S t e p F o r w a r d i n H a n t o r d ' s C l e a n u p Process 09 K e n n e t h M. N o r r i s ~i c e o f E r t e r n a l~a i n IXI D. J. Dunn

Interpretation of large‐scale, long‐term electrical geophysical monitoring guided by a process simulation

“…The profiles were organized as a grid to fill in areas that were not directly overlapping the cribs and trenches (Figure 4). Additionally, the ERT lines were extended past the crib and trench boundaries into adjacent properties to delineate the edges of the plume (Benecke et al., 2006; Rucker & Fink, 2007). Along each profile, most of the electrodes were spaced at 3 m, and several were spaced 6 m apart.…”

“…ERT has been used at waste sites to characterize plume extents (Bichet et al., 2016; Chambers et al., 2006; Liao et al., 2018; Maurya et al., 2017; Ugbor et al., 2021) in conjunction with tracer tests (Cassiani et al., 2006; Wilkinson et al., 2010) and pumping tests (Vogelgesang et al., 2020) for hydrologic characterization. ERT monitoring has also been used to image contaminant migration and solute transport (Casado et al., 2015; Kemna et al., 2002; Kuras et al., 2016), infer the distribution of vadose zone contaminants (Benecke et al., 2006; T. C. Johnson & Wellman, 2013; Rucker & Fink, 2007), and identify the preferential flow paths of surface water intruding into groundwater (T. C. Johnson et al., 2012, 2015; Robinson et al., 2023; Wallin et al., 2013). Recent reviews (Dimech et al., 2022; Slater & Binley, 2021) recognized long‐term resistivity monitoring as a useful tool to identify and follow inorganic contaminants, and Dimech et al.…”

“…Several borehole geophysical studies (Brodeur et al., 1993; Fecht et al., 1977; Horton & Randall, 2000) and geologic, geochemical, and hydraulic measurements (Serne et al., 2009) were conducted to assess that contaminants had not reached groundwater. They found that there was ongoing but limited vertical migration to approximately 70 m below ground surface but concluded that contaminants did not reach the water table, reported at a depth of 104 m (Benecke et al., 2006).…”

“…To supplement and further validate these studies, surface ERT data were collected to identify regions impacted by past discharges of liquid waste composed primarily of high sodium and nitrate concentrations (Benecke et al., 2006; Rucker & Fink, 2007). The ERT surveys consisted of a dense collection of 55 lines in a 2D orthogonal grid‐like pattern on the surface of the site and took place in 2004, 2005, and 2006 (Benecke et al., 2006; Rucker & Fink, 2007). A qualitative 3D interpretation was made by interpolating 2D spatial interpretations of the ERT data, a strategy termed high‐resolution resistivity (HRR).…”

“…A qualitative 3D interpretation was made by interpolating 2D spatial interpretations of the ERT data, a strategy termed high‐resolution resistivity (HRR). However, the authors acknowledged the limitations associated with this depth estimation method, where the 2D data analysis was translated to a 3D interpretation (Benecke et al., 2006). To address this shortcoming and solve for the true distribution of subsurface electrical conductivities, Rucker et al.…”