Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAP• In all cases, the initial soil samples from a location will be analyzed for all 18 ROIs. Inselected cases, samples will also be analyzed for the additional 12 potential ROIs (seeSection 6.2 for a description of which samples would be selected for analysis of theadditional 12 potential ROIs). If initial analyses indicate that only a limited set ofradionuclides are present, then subsequent sample analyses used to vertically or laterallybound contamination will be limited to those radionuclides originally identified as beingabove background conditions.• Characterization of subsurface soils beneath hardstands may be deferred until afterhardstands are removed as part of Phase 1 DP activities to facilitate access to subsurfacesoils.6.7 Determine Level and Extent of Sediment ContaminationThe Phase 1 DP defines CG requirements for sediments. These requirements are applicable tospecific reaches of Erdman Brook and Franks Creek as identified in Figure 6. All other sedimentsassociated with drainage features on the WVDP premises will be subject to surface soil CGrequirements.CSAP data collection from Erdman Brook and Franks Creek sediments will be used to evaluatethe presence and extent of sediment contamination that exceed sediment CG requirements. Thissampling is confined to to the specific reaches of Erdman Brook and Franks Creek as identified inFigure 6. The strategy has two basic components:• GWS data will be collected from the reaches of concern as practicable. Biased sedimentsampling will occur in response to the identification of anomalies in the GWS data.Biased sampling will consist of samples from the surface to a depth of 15 cm that targetthe highest gross activity readings. In the event that a sample identifies contaminationimpacts above background levels, a second sample from the same location representing adepth of 15 cm to 1 m will be analyzed. In the event that sample identifies contaminationimpacts above background, a third sample from the same location representing a depth of1 to 2 m will be analyzed. This process will continue until contamination impacts abovebackground conditions are vertically bounded.Rev. 1 38