Corrective Action Investigation plan for Corrective Action Unit 263: Area 25 Building 4839 Leachfield, Nevada Test Site, Nevada, March 1999

The Corrective Action Investigation Plan for Corrective Action Unit 263, the Area 25 Building 4839 Leachfield, has been developed in accordance with the Federal Facility Agreement and Consent Order that was agreed to by the US Department of Energy, Nevada Operations Office; the Nevada Division of Environmental Protection; and the US Department of Defense. Corrective Action Unit 263 is comprised of the Corrective Action Site 25-05-04 sanitary leachfield and associated collection system. This Corrective Action Investigation Plan is used in combination with the Work Plan for Leachfield Corrective Action Units: Nevada Test Site and Tonopah Test Range, Nevada (DOE/NV, 1998d). The Leachfield Work Plan was developed to streamline investigations at Leachfield Corrective Action Units by incorporating management, technical, quality assurance, health and safety, public involvement, field sampling, and waste management information common to a set of Corrective Action Units with similar site histories and characteristics into a single document that can be referenced. This Corrective Action Investigation Plan provides investigative details specific to Corrective Action Unit 263. Corrective Action Unit 263 is located southwest of Building 4839, in the Central Propellant Storage Area. Operations in Building 4839 from 1968 to 1996 resulted in effluent releases to the leachfield and associated collection system. In general, effluent released to the leachfield consisted of sanitary wastewater from a toilet, urinal, lavatory, and drinking fountain located within Building 4839. The subsurface soils in the vicinity of the collection system and leachfield may have been impacted by effluent containing contaminants of potential concern generated by support activities associated with the Building 4839 operations