Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPtaken every 15 cm vertically. The purpose of these samples is to define the vertical extentof contamination. [contingent]J.9.4Sediment SamplingThe purpose of sediment sampling within WMA 12 South is to determine the presence and lateralextent of contamination above sediment CG w requirements, and the vertical extent of sedimentcontamination impacts above background levels, for those portions of Erdman Brook and FranksCreek where the sediment CG requirements apply. The areas shaded as part of the sediment CSMin Figure J.13 indicate the portions of Erdman Brook and Franks Creek to which sediment CGrequirements apply. For all other portions of Erdman Brook and Franks Creek, and any otherdrainage feature in WMA 12 South, the surface soil CG requirements apply.• One surface sediment sample will be collected to a depth of 15 cm from a biased locationin the vicinity of the confluence of Erdman Brook and Franks Creek. The location will beselected based on GWS data. Its location will be selected so that it targets the locationmost likely to contain significant contamination. Besides the 18 ROI it will also beanalyzed for the 12 radionuclides of potential interest. The purpose of this sample is toevaluate the appropriateness of the current ROI list and to verify the absence of additionalROI. [required]• One surface sediment sample will be collected to a depth of 15 cm from a biased locationimmediately downstream of the Equalization Basin discharge to Erdman Brook. Thelocation will be selected based on GWS data. Its location will be selected so that it targetsthe location most likely to contain significant contamination. Besides the 18 ROI it willalso be analyzed for the 12 radionuclides of potential interest. The purpose of this sampleis to evaluate the appropriateness of the current ROI list and to verify the absence ofadditional ROI. [required]• Systematic sediment sampling will focus on those portions of Erdman Brook consideredmost likely (based on GWS and historical sampling) to potentially have contaminationabove the CG w requirements for sediments. Figure J.13 shows the portions of ErdmanBrook and Franks Creek where the sediment CG requirements apply and the portion ofErdman Brook that possibly has contamination above sediment CG w requirements basedRev. 1 J-13