Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPWMA 5 is underlain by the sand and gravel unit which overlies the Lavery Till. The sand andgravel unit has been subdivided into the Thick Bedded Unit (TBU) and the underlying SlackWater Sequence (SWS). The SWS is only present in WMA 5 along the boundary separatingWMA 5 from WMA 2. Groundwater in the sand and gravel unit flows to the northeast across theNorth Plateau. Groundwater eventually discharges to ditches draining the site and to seeps alongQuarry Creek to the north, and Franks Creek to the east. The Lavery Till has low permeability butgroundwater does flow vertically downward through this unit recharging the underlying KentRecessional Sequence.Approximately five acres of WMA 5 are currently covered by asphalt or compacted gravel. Anadditional 2.5 acres are covered by building foundations.The majority of WMA 5’s soil surface has been reworked at least once since the inception of thesite.E.3 Area HistoryFigure E.3 shows WMA 5 in 1962, prior to site development. At this time, a road passed throughthe WMA 5 area and the majority of its surface was farmed (with the exception of wetlands in thenortheast portion of WMA 5).Figure E.4 shows WMA 5 in 1966, after site development began. Approximately four acres in itssouth central area had been cleared and the Old Hardstand is clearly visible (approximately 0.75acres in size).Figure E.5 shows WMA 5 in 1968. No further development of the area is visible.Figure E.6 shows WMA 5 in 1977. No further development of the area is visible.Figure E.7 shows WMA 5 in 1984. The Lag Storage Building has been added to WMA 5 and theOld Hardstand is clearly delineated in this photograph.Rev. 1 E-4