Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPand analyzed from that location. This process will continue until the vertical extent ofcontamination above background is bounded. One down-hole gamma scan will beconducted from each soil location requiring deeper investigation with a static readingtaken every 15 cm vertically. The purpose of these samples is to define the vertical extentof contamination. [contingent]F.9.5Drainage Feature SamplingWMA 6 contains three distinct drainage features, the current WMA 6 drainage ditch, the reach ofErdman Brook that passes through WMA 6, and a drainage ditch the feeds Erdman Brook fromthe south (Figure F.1). For drainage features within WMA 6, the surface soil CG w requirementsapply. Surface drainage feature sampling will be conducted to determine ditch sedimentcontamination status relative to surface soil CG w requirements. Surface drainage features will besampled as follows:• Samples representing a 0-15 cm depth interval will be collected from ditch sediments. InWMA 6, the three 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 15cm-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]F.9.6Buried Infrastructure Soil SamplingSoils associated with buried infrastructure within WMA 6 will be sampled to determine theircontamination status.Rev. 1 F-18