Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPWMA 7 contains two distinct drainage features, one along the eastern boundary of the NDA anda second along the northern boundary. For drainage features within WMA 7, the surface soil CG wrequirements apply. Surface drainage feature sampling will be conducted to determine ditchsediment contamination status relative to surface soil CG w requirements. Surface drainagefeatures will be sampled as follows:• Samples representing a 0-15 cm depth interval will be collected from ditch sediments. Inaddition, ditch sampling along the eastern boundary will include samples representing a15 cm-1 m depth interval. In WMA 7, the two ditches have a combined length ofapproximately 90 m. Samples will be systematic located using a random start, separatedby 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]• The two WMA 7 drainage features combine to feed Erdman Brook in WMA 12 South. Ifditch contamination above surface soil CG w requirements is encountered that extends tothe boundary with WMA 12 South, sampling will continue with a 30 m spacing intoWMA 12 South following the drainage feature until contamination above surface soilCG w requirements is bounded or the portion of Erdman Brook is encountered wheresediment CG requirements apply. [contingent]G.9.6 Buried Infrastructure Soil SamplingSoils associated with buried infrastructure within WMA 7 will be sampled to determine theircontamination status.Rev. 1 G-15