Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAP• If any 0-15 cm surface soil sample result indicates contamination impacts abovebackground levels and there was not a 15 cm-1 m sample collected from that location, a15 cm-1 m sample will be collected from that location following the protocols used forthe original 0-15 cm surface soil sample. In addition, each soil location will have onedown-hole gamma scan conducted at the center of the location with static measurementstaken every 15 cm. [contingent]• If systematic subsurface sampling identified contamination that appears to extendlaterally beyond the grid boundaries in WMA 5, then the grid will be extended andadditional sampling conducted until the lateral extent of contamination has been bounded.[contingent]E.9.5Drainage Feature SamplingWMA 5 contains two primary drainage features. The first runs from the New Hardstand to theWVDP fence line in the northeast corner of WMA 5 (Figure E.1), discharging at locationWSNSW74A. The second runs north-to-south along the western edge of the paved WMA 5 area.For drainage features within WMA 5, the surface soil CG w requirements apply. Surface drainagefeature sampling will be conducted to determine ditch sediment contamination status relative tosurface soil CG w requirements. Surface drainage features will be sampled as follows:• Samples representing a 0-15 cm depth interval will be collected from ditch sediments. InWMA 5, the primary drainage features have a combined length of approximately 360 m.Samples will be systematic located using a random start, separated by 30 m. [required]• If any 0-15 cm sample result indicates contamination impacts above background levelsand a 15 cm-1 m sample was not also collected, a 15 cm-1 m sample will be collectedfrom that location following the protocols used for the original 0-15 cm sample.[contingent]• If a sample indicates contamination impacts above background levels for the 15 cm -1 mdepth interval, an additional sample from a depth of 1-2 m will be collected and analyzedfrom that location. This will be repeated, as necessary, until the vertical extent ofcontamination impact is bounded at that location. [contingent]Rev. 1 E-17