Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPoIf GWS results indicate areas with surface soil contamination impacts but it isunclear whether surface soil CG w requirement exceedances are present, at mostfive sampling locations will be selected that systematically cover the areas ofinterest. One sample will be collected from each location representative of a 0 –15 cm depth interval and one representative of the 15 cm – 1 m depth interval.Locations will be selected to provide systematic coverage of the area of interest.The purpose is to resolve the question of whether surface soil CG w requirementexceedances exist for areas where GWS results are ambiguous. [contingent]oIf any 0-15 cm interval yields a sample result indicating a surface soil CG wrequirements exceedance and that sample location is not laterally bounded eitherby existing sampling locations with results less than surface soil CG wrequirements or by GWS data that clearly indicate contamination is not aconcern, additional sampling locations will be selected so that the contaminationencountered is spatially bounded. Sampling to laterally bound contamination mayextend, if necessary, into WMA 10 and/or WMA 12. The purpose is to laterallybound contamination that is above CG w requirements. [contingent]F.9.4Subsurface Soil SamplingThe purpose of subsurface soil sampling within WMA 6 is to determine presence and verticalextent of contamination impacts above background levels. There are several areas within WMA 6that have specific subsurface soil contamination concerns that are discussed below. These includesubsurface soils associated with the boundaries with WMA 1 and WMA 2, the two DemineralizerSludge Ponds, the New Sewage Treatment Plant, and the original footprint of the Old SewageTreatment Plant discharge ditch.• Systematic subsurface sampling along the northern boundary of WMA 6 will take placeas part of WMA 1 and WMA 2 pre-remediation CSAP activities; that sampling mayextend into WMA 6 as necessary to laterally bound contamination that may beencountered. WMA 1 and 2 data collection activities are described in the Appendices Aand B, respectively.Rev. 1 F-15