Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPseparated by 10 m (Figure A.23). At each location, one core that extends 1 m into theLavery Till will be retrieved. A down-hole scan will be conducted to the extent possibleat each location with a static measurement every 30 cm. Each core will be divided into 1m segments.oA variety of geotechnical field data will be collected from each core location, asnecessary and required for sheet piling/slurry wall design. In addition soil sampleswill be collected and submitted for geotechnical analyses (e.g., grain size, Atterberglimits, triaxial strength, etc.) as required by sheet piling/slurry wall design.[required]oAt minimum, the following soil core segments will be submitted for laboratoryradiological analysis: the top meter (representative of surface soils), the meterdirectly above the Lavery Till, the top meter of Lavery Till, and the meter straddlingthe water table. In addition, if the bore/core scan identifies an elevated zone notincluded in one of these three, the meter interval containing the elevated zone will besubmitted for laboratory radiological analysis. [required]oFrom each location three groundwater samples will be collected: one from the watertable, one from immediately above the Lavery Till, and one midway between thesetwo, if possible. [required]oIf any interval other than the top 1 m identifies contaminants above backgroundlevels, then additional soil core locations will be placed on a triangular grid with aseparation of 10 m to from the location(s) of concern in a manner that bounds theoriginal contamination as the terrain allows and sampled as described above. Thisprocess will continue until the lateral extent of subsurface contamination is boundedoutside the planned excavation footprint. If extensive subsurface contamination isencountered a field decision may be made to increase the separation distance betweenthe original set of core locations and the next set of bounding core locations. Theultimate intent is to spatially bound subsurface contamination to the south, west, andnorth of the planned WMA 1 excavation. This sampling may extend into WMA 3,10, and 6 as necessary. In the case of WMA 3, sampling will not extend beyond theplanned slurry wall footprint. [contingent]Rev. 1 A-17