Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPBrook northwest of the NDA and continues in a northerly direction to WMA 2. In 2009,NYSERDA and DOE completed erosion mitigation work on Erdman Brook and part of LagoonRoad Creek, just to the northwest of the NDA and SDA. The work included the realignment ofthe stream channel, grading of a knickpoint, lining the new channel with geotextile and placingmedium stone fill on top. The work was necessary to keep surface water flow in a central channelto ensure continued stability of the North Slope of the SDA.Aside from these features, WMA12 has been relatively undisturbed by Nuclear Fuel Services(NFS), NYSERDA, or WVDP activities.J.3 Area HistoryWMA 12 South was not used for any structural purposes during the lifespan of the NFS andWVDP activities; however, WMA 12 South supported NFS and WVDP operations. Both NFSand the WVDP discharged untreated (pre-1971) and treated (post-1971) low-level wastewater toErdman Brook and Franks Creek in WMA 12 South.Figure J.2 shows WMA 12 South in 1962 prior to site development. At this time a significantfraction of WMA 12 South was wooded, with the balance appearing to have been farmed.Figure J.3 shows WMA 12 South in 1966. At this stage the adjacent WMA 2 lagoons wereactively being used. A soils push-out area is visible that extends from WMA 2 into WMA 12South. This push-out area is of significance because it corresponds to elevated direct gammareadings collected in 1990-1991.Figure J.4 shows a 2007 aerial photo of the WMA 12 South area. The push-out area is still visibleas a grass-covered area adjacent to WMA 2.J.4 Known and Suspected ReleasesJ.4.1Drainage Feature Contamination by Deposition / RunoffPotentially Affected Media:Potentially Affected WMAs:subsurface soils, surface water, sediment1, 6, 7, 12 (southern portion) (Erdman Brook)Rev. 1 J-2