Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPand subsurface contamination resulting from contaminant migration via groundwater from theProcess Building.After initiation of the WVDP, the surface of WMA 3 underwent significant reworking. Thisreworking may have covered contaminated soils with clean cover, removed contaminated surfacesoils for disposition elsewhere, and/or re-used contaminated soils as backfill for buildingfoundations or buried infrastructure.Groundwater flow underneath WMA 3 is expected to be, in general, towards the northeast.Consequently one would expect a greater likelihood for groundwater contamination as one movesfrom west to east (assuming releases within the WMA 3 footprint) and from south to north(assuming impacts from contaminated groundwater originating with Process Building activities).Figure C.16 shows the current CSM for surface soils. Figure C.17 shows the CSM for soilsdeeper than 1 m. Figure C.18 shows the CSM for contaminated groundwater beneath WMA 3.C.8 WMA 3-Specific Characterization Goals• Develop an inventory of buried infrastructure• Evaluate appropriateness of the current list of Radionuclides of Interest (ROI)• Verify absence of additional ROI• Determine level and extent of surface contamination• Identify the presence/absence of subsurface soil contamination• Identify soil waste stream characteristics• Define required extent of WMA 1 excavation• Obtain data to support Phase 2 planningC.9 CSAP Pre-Remediation Data Collection and Associated Decision-MakingCSAP pre-remediation data collection will consist of a number of components described in moredetail below.Rev. 1 C-11