Conceptual Site Model - Argonne National Laboratory

WVDP Phase 1 CSAPAPPENDIX BWMA 2 PRE-REMEDIATION DATA COLLECTIONB.1 BackgroundWaste Management Area 2 (WMA 2) is approximately 14 acres in size (see Figures B.1 and B.2for maps). WMA 2 includes facilities historically used for managing low-level radioactivewastewater generated on site.Descriptions of the various features of WMA 2 follow, and are taken from the Phase 1 DP,Section 3.1.2:Low-Level Wastewater Building. The Low-Level Wastewater (LLW2) Building is locatedtowards the center of WMA 2, southwest of Lagoon 4. This pre-engineered, single-story, metalsidedbuilding rests on a concrete wall foundation, measuring 40 feet by 60 feet. The buildinghouses two skid-mounted process equipment modules that are used to treat wastewater fromWMA 1 and WMA 2, and radiologically contaminated groundwater from the WMA 7 NDAInterceptor Trench, groundwater collected from within the tank farm in WMA-3, andgroundwater collected from the North Plateau Groundwater Recovery System. The LLW2Building was built in 1998 to replace the adjacent O2 Building. The O2 Building was the originallow-level wastewater treatment facility that was built by NFS in 1971, decommissioned in the1990s, and demolished to slab in 2006 (see discussion of O2 Building below).Lagoons. From 1965 to 1971, low-level wastewater was routed from the Old and/or NewInterceptors through Lagoons 1, 2, and 3 in series before discharge to Erdman Brook. In 1971, thelow-level waste treatment facility system was installed; this system initially consisted of the O2Building and Lagoons 4 and 5, and now consists of the LLW2 Building and Lagoons 4 and 5.Between 1971 and 1982, low-level wastewater was routed sequentially from the Interceptorsthrough Lagoon 1, Lagoon 2, and the O2 Building for treatment, then to Lagoon 4 or 5, andfinally to Lagoon 3 before discharge to Erdman Brook. Lagoon 1 was closed in 1984; from 1984to the present, low-level wastewater has been routed sequentially through Lagoon 2, the O2Building or LLW2 Building for treatment, Lagoon 4 or 5, and finally to Lagoon 3 beforedischarge to Erdman Brook through a permitted outfall (SPDES WNSP001).Rev. 1 B-1