Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPpurpose is to resolve the question of whether CG w requirement exceedances existfor areas where GWS results are ambiguous. [contingent]oIf any 0-15 cm interval yields a sample result indicating a CG w requirementsexceedance and that sample location is not laterally bounded either by existingsampling locations with results less than CG w requirements or by GWS data thatclearly indicate contamination is not a concern, additional sampling locationswill be selected so that the contamination encountered is spatially bounded. Thepurpose is to laterally bound contamination that is above CG w requirements.[contingent]K.9.3 Subsurface Soil SamplingThe purpose of subsurface soil sampling within WMA 12 North is to determine the vertical extentof contamination impacts above background levels.• If any 0-15 cm surface soil sample result indicates contamination impacts abovebackground levels and there was not a 15 cm-1 m sample collected from that location, a15 cm-1 m sample will be collected from that location following the protocols used forthe original 0-15 cm surface soil sample. In addition, each soil location will have onedown-hole gamma scan conducted at the center of the location with static measurementstaken every 15 cm. [contingent]• If a surface soil sample indicates contamination impacts above background levels for the15 cm-1 m depth interval, an additional sample from a depth of 1-2 m will be collectedand analyzed from that location. This process will continue until the vertical extent ofcontamination above background is bounded. One down-hole gamma scan will beconducted from each soil location requiring deeper investigation with a static readingtaken every 15 cm vertically. The purpose of these samples is to define the vertical extentof contamination. [contingent]K.9.4 Required Laboratory AnalysesRev. 1 K-8