Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPI.2 Physical SettingWMA 10 is relatively flat. WMA 10 is bordered to the west by the WVDP premises fence line, tothe north by WMA 5, to the east by WMA 3, WMA 1, WMA 6, and WMA 9, and to the south bythe WVDP premises fence line. A significant portion of WMA 10’s surface area (11 acres) iscovered by concrete, asphalt, or gravel as part of roads, parking lots, and hardstands. There areonly a few structures with relatively small footprints within WMA 10. The balance of WMA 10 isvegetated. WMA 10 is divided into a portion that is on the North Plateau and a portion that is onthe South Plateau, with Erdman Brook the divider.A relatively small portion of WMA 10 in the north has surface drainage captured by a stormsewer system that directs it north and off-premises. The majority of surface drainage from WMA10 falls in Erdman Brook’s watershed and is captured by Erdman Brook, which passes west toeast through the center of WMA 10.The northern half of WMA 10 is underlain by the sand and gravel unit which overlies the LaveryTill. In general, groundwater in the sand and gravel unit flows to the northeast across the NorthPlateau although there probably is also localized discharge to Erdman Brook. The Lavery Till haslow permeability but groundwater does flow vertically downward through this unit recharging theunderlying Kent Recessional Sequence.The weathered Lavery Till is exposed at the surface in the southern half of WMA 10.Groundwater in the weathered Lavery Till flows to the northeast across the South Plateau withlikely discharge to Erdman Brook.The majority of WMA 10’s surface has been reworked since 1981.I.3 Area HistoryFigure I.3 shows WMA 10 in 1962, prior to site development. As can be seen in this photograph,much of the WMA 10 area was farmed and/or farmsteads. A public road passed north-souththrough the southeastern portion of WMA 10.Rev. 1 I-3