Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPtaken every 15 cm. The purpose is to document surface soil CG w requirementexceedances and bound the lateral extent of contamination. [contingent]oIf 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 0-15cm depth interval. Locations will be selected to provide systematic coverage ofthe area of interest. The purpose is to resolve the question of whether surface soilCG w requirement exceedances 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. The purpose is to laterally boundcontamination that is above CG w requirements. [contingent]• The area where surface soil contamination is potentially overlain by pavement or a layerof clean backfill (see Figure E.16, approximately 9 acres) will undergo systematicsampling for surface soil contamination concerns. Sampling locations will be arranged ona systematic triangular grid with a grid separation of 20 m. One soil sample will becollected from each location representative of a 0-1 m depth. Down-hole gamma data willbe collected from each location with static measurements collected for every 15 cm depthinterval. An estimated 120 locations will undergo this data collection. [required]E.9.4Subsurface Soil SamplingThe purpose of subsurface soil sampling within WMA 5 is to determine the presence and verticalextent of contamination impacts above background levels. There are several areas within WMA 5that have subsurface soil contamination concerns that are discussed below. These include areasalong the New Hardstand that were originally drainage features but subsequently filled in withRev. 1 E-15