Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPoIf GWS results indicate surface soil contaminant levels exceeding surface soil CG wrequirements likely exist, one sampling location will be selected at the highest grossactivity level to confirm surface soil CG w exceedances and another set of samplinglocations will be identified to spatially bound the extent of contamination (i.e., alongthe boundary of what is considered likely above surface soil CG w requirements) ifthis is not obvious from the GWS data. Two samples will be collected from thelocation targeting high gross activity levels, one representative of a 0 – 15 cm depthinterval, and one representative of a 15 cm – 1 m depth interval. One sample will becollected from each location intended to laterally bound contamination,representative of a 0-15 cm depth interval. In addition, the location targeting highgross activity levels will have a down-hole gamma scan conducted with staticmeasurements taken every 15 cm. The purpose is to document surface soil CG wrequirement exceedances and bound the lateral extent of contamination. [contingent]oIf GWS results indicate areas with surface soil contamination impacts but it is unclearwhether surface soil CG w requirement exceedances are present, at most five samplinglocations will be selected that systematically cover the areas of interest. One samplewill be collected from each location representative of a 0-15 cm depth interval. Thepurpose 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 either byexisting sampling locations with results less than surface soil CG w requirements or byGWS data that clearly indicate contamination is not a concern, additional samplinglocations will be selected so that the contamination encountered is spatially bounded.The purpose is to laterally bound contamination that is above CG w requirements.[contingent]In addition, because of the pavement/surface cover present for much of WMA 1 and thesignificant amount of surface soil reworking that occurred historically, contamination inthe top 1 m of soils may be covered by clean material/pavement and may not be readilydetectable by GWS scans. Areas of WMA 1 that are outside the planned excavationfootprint will be systematically sampled to a depth of 1m. Systematic sampling locationsRev. 1 A-15