Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPA complete (100%) logged gamma walkover survey (GWS) will be conducted for accessibleareas within WMA 10 including paved areas. Examples of areas that would not be accessible areareas where standing water is present in wetlands or ponds and the footprints of existingbuildings. Based on the GWS results, surface soil areas within WMA 10 will be divided into fourcategories: (1) surface soils where GWS data indicate contamination above CG w requirements;(2) surface soils where GWS data indicate contamination, but it is not clear if contaminationexceeds surface soil CG w requirement; (3) surface soils where GWS indicate impacts, but thoseimpacts are not expected to exceed surface soil CG w standards; and (4) surface soils where thereis no indication of impacts above background conditions. The purpose of this data collection is toprovide insights into the spatial distribution of surface contamination, and to guide subsequentsoil sampling. [required]I.9.3Surface Soil SamplingSurface soil sampling will be used to address areas inaccessible to GWS data collection, toresolve hot spots identified by the GWS data, and to evaluate the presence, absence, and/or extentof surface contamination above CG w requirements based on GWS results.• Wetlands. It is possible that standing water will be present in wetlands that prevent GWSdata collection from those areas. Consequently, soil sampling will be required for wetlandfootprints and for any other areas where standing water prevents the collection of GWSdata.For every area where standing water or saturated soil conditions prevent GWS datacollection, systematic soil sampling will take place. For wetland areas less than 200 m 2 insize, one sample will be collected. For areas between 200 and 1,000 m 2 in size, onesample per 200 m 2 will be collected. For areas between 1,000 and 2,500 m 2 in size, fivesamples will be collected. For areas exceeding 2,500 m 2 in size, at minimum one samplewill be collected per 500-m 2 area. One sample will be collected from each locationrepresentative of a 0-15 cm depth interval. In the case where an area has more than onelocation, locations will be selected to provide systematic coverage of the area of interest.[contingent]Rev. 1 I-10