Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAP• Define required extent of WMA 1 excavation• Obtain data to support Phase 2 planning• Obtain geotechnical data required for barrier wall designA.9 CSAP Pre-Remediation Data Collection and Associated Decision-MakingCSAP pre-remediation data collection will consist of a number of components described in moredetail below.A.9.1Buried InfrastructureThe footprint of buried infrastructure will be identified and mapped with a focus on areas outsidethe planned excavation and infrastructure that crosses into the planned excavation. A significantamount of buried infrastructure is believed to exist within WMA 1, and in particular in thewestern portion of WMA 1. This infrastructure would include waste and wastewater lines as wellas other buried utilities. [required]A.9.2Gamma Walkover Survey DataThe purpose of performing a gamma walkover survey of the WMA 1 area is to identify the leveland extent of surface contamination. This includes both general trends in average activityconcentrations pertinent to the surface soil CG w requirement, as well as the identification ofisolated, more-elevated anomalies that might be indicative of discrete releases and/or surface soilCG emc concerns.A complete (100%) logged gamma walkover survey (GWS) will be conducted for accessibleareas within WMA 1. Examples of areas that would not be accessible are existing buildingfootprints and building pads. Based on the GWS results, surface soil within WMA 1 will bedivided into four categories: (1) surface soils where GWS data indicate contamination above CG wrequirements; (2) surface soils where GWS data indicate contamination, but it is not clear ifcontamination exceeds surface soil CG w requirement; (3) surface soils where GWS indicateimpacts, but those impacts are not expected to exceed surface soil CG w standards; and (4) surfacesoils where there is no indication of impacts above background conditions. The purpose of thisRev. 1 A-13