Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPwill be defined as soil immediately beneath the cover. If sampling or GWS data indicate thatcontamination may exist beneath existing structures (e.g., the NDA geomembrane cover or thehardstand area), then sampling locations will be offset along the foundation/hardstand edge todetermine contamination extent. The purpose of the offset is to allow safe acquisition of data.Data collection through the NDA geomembrane cover or through hardstands in WMA 7 will notbe required as part of this effort.G.9.8 Required Laboratory AnalysesAll samples will be submitted for analysis of all 18 ROI.A select portion of the samples as described above may be analyzed for the additional12 radionuclides of potential interest. If these sample results indicate the presence of the one ormore of those radionuclides at levels of potential significance, then the balance of samples fromWMA 7 will also be analyzed for the additional radionuclides that were identified.Table G.2 summarizes the required sample numbers and the estimated number of contingencysamples for WMA 7.This sampling plan assumes that quick turn-around analyses are available for Sr-90 and Cs-137and that soil samples will be screened for Sr-90 and Cs-137 prior to being analyzed for thebalance of the ROI. Contingency sampling requirements as described above may be undertakenbased on these screening data.G.9.9 Decision-Making SummaryA summary of decision-making based on the WMA 7 data is as follows:• If buried infrastructure of concern in addition to the Interceptor Trench and LeachateTransfer Line is identified, then biased locations will be selected, excavation conductedto expose the trench/line, and at least one biased sampled collected. If contamination isencountered above CG w requirements, sampling will continue along the trench/lines untilit is bounded.Rev. 1 G-17