Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPpotentially exceeds surface soil CG levels. Instead, gamma walkover data will be mapped and reviewed toidentify spatial trends or localized anomalies that are indicative of the potential presence of contamination(i.e., gross activity results that are not consistent with presumed background conditions). This qualitativereview will be combined with the use of the field investigation level derived from reference area FIDLERdata to identify locations for biased soil sampling where FIDLER data suggest impacts inconsistent withbackground conditions.11.4 ProtocolsGross gamma activity surveys will use the following protocols:• All gross gamma activity surveys will be conducted in a manner that allows the resulting data tobe matched to coordinates and electronically logged.• In general, measurement acquisition time will be 1 second.• Surface scans will be conducted in a manner that provides at least one measurement per squaremeter.• In general, surveys will be conducted with the detector approximately 15 cm from the groundsurface.• In general, surveys will be conducted by walking parallel lines with the detector swung in aserpentine fashion.• In the event that a clearly elevated area has been identified, the field technician will collectadditional static readings in the vicinity to more clearly define the footprint of the elevated area.• In the event that shine is potentially present (see Section 11.5), steps will be taken to mitigate theeffects of the shine on survey data quality.• Scans will be electronically logged. Each measurement record will include a detector identifier, atechnician identifier, a date and time stamp, coordinate information, a qualifier indicatingcoordinate measurement quality, and the gross activity observed (either as counts per minute orRev. 1 84