Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPC.9.1Buried InfrastructureThe footprint of buried infrastructure will be identified and mapped. There is believed to be asignificant quantity of buried infrastructure within the WMA 3 area that would be of potentialinterest. [required]C.9.2Gamma Walkover Survey DataThe purpose of performing a gamma walkover survey of the WMA 3 area is to identify the leveland extent of surface contamination. This includes both general trends in average activityconcentrations pertinent to the surface soil CG w requirement, as well as the identification ofisolated, more-elevated anomalies that might be indicative of discrete releases and/or surface soilCG emc concerns.A complete (100%) logged gamma walkover survey (GWS) will be conducted for accessibleareas within WMA 3. Examples of areas that would not be accessible are areas where there areexisting building footprints and building pads. Based on the GWS results, surface soil withinWMA 3 will be divided into four categories: (1) surface soils where GWS data indicatecontamination above CG w requirements; (2) surface soils where GWS data indicatecontamination, but it is not clear if contamination exceeds surface soil CG w requirement; (3)surface soils where GWS indicate impacts, but those impacts are not expected to exceed surfacesoil CG w standards; and (4) surface soils where there is no indication of impacts abovebackground conditions. The purpose of this data collection is to provide insights into the spatialdistribution of surface contamination, and to guide subsequent soil sampling. Because of theexisting surface cover within the WMA 3 area, the area that can be confidently assessed forsurface contamination by GWS may be limited. [required]C.9.3Surface Soil SamplingBecause of the existing surface cover which is expected to be found over the majority of theWMA 3 area, GWS data collection will be supplemented with systematic surface soil sampling,in addition to biased surface soil sampling that will be conducted in response to elevated GWSdata that might be indicative of hot spots.Rev. 1 C-12