Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPoIf 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.Sampling to laterally bound contamination will not compromise the NDAgeomembrane cover or extend into WMA 8, but may extend, if necessary, intoWMA 12 and/or WMA 6. The purpose is to laterally bound contamination that isabove CG w requirements. [contingent]G.9.4 Subsurface Soil SamplingThe purpose of subsurface soil sampling within WMA 7 is to determine presence and verticalextent of 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 the15cm-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]G.9.5 Drainage Feature SamplingRev. 1 G-14