Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPdrainage feature sampling will be conducted to determine ditch sediment contamination statusrelative to surface 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 4, the primary drainage features have a combined length of approximately 450 m.Samples will be systematic located using a random start, separated by 30 m. Thissampling will not address the buried portion of the Swamp Ditch along the north side ofthe CDDL. [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]D.9.5Additional ContingenciesSampling and/or GWS data may indicate that contamination exists or extends beneath surfacescurrently covered by existing structures, concrete, asphalt, or gravel. In this case, “surface soil”will be defined as soil immediately beneath the cover. If sampling or GWS data indicate thatcontamination may exist beneath existing structures (e.g., the CDDL), then sampling locationswill be offset along the foundation edge to determine contamination extent. The purpose of theoffset is to allow safe acquisition of data. Data collection through the CDDL in WMA 4 will notbe required as part of this effort.D.9.6Required Laboratory AnalysesAll samples will be submitted for analysis of all 18 ROI.Rev. 1 D-12