Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPA select portion of the samples as described above will 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 12 South will also be analyzed for the additional radionuclides that were identified.Table J.2 summarizes the required sample numbers and the estimated number of contingencysamples for WMA 12 South.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.J.9.7Decision-Making SummaryA summary of decision-making based on the WMA 12 South data is as follows:• If GWS indicate anomalies are present, biased samples will be selected to target thoseanomalies.• If biased sample results for the 15 cm-1 m depth interval indicate contamination impactsabove background, an additional sample from that location representing the depth interval1-2 m will be collected and this process repeated until contamination is verticallybounded.• The WMA 12 South surface soil area classification as contained in Figure J.12, and thesediment classification as contained in Figure J.13, will be adjusted based on GWSresults. These adjustments may affect systematic sample number requirements,particularly for sediments.• If the results from the biased sediment sample taken from the confluence of Franks Creekand Erdman Brook indicate one or more of the twelve radionuclides of potential interestRev. 1 J-16