Closure plan for CAU No. 93: Area 6 steam cleaning effluent ponds, Nevada Test Site

The steam cleaning effluent ponds (SCEP) waste unit is located in Area 6 at the Nevada Test Site (NTS). Nevada Operations Office operates the NTS and has entered into a trilateral agreement with the State of Nevada and the Defense Special Weapons Agency (DSWA). The trilateral agreement provides a framework for identifying, characterizing, remediating, and closing environmental sites on the NTS and associated bombing ranges. The SCEP waste unit consists of: two steam cleaning effluent ponds; layout pad and associated grease trap; Building 6-623 steam cleaning pad; test pad; Building 6-623 grease trap; Building 6-800 steam cleaning pad; Building 6-800 separator; Building 6-621 sump; and the concrete asbestos piping connecting these components to both SCEPs. Clean closure is the recommended closure strategy for the majority of the components within this CAU. Four components of the unit (Building 6-621 Sump, Test Pad Grease Trap, Building 6-623 Steam Cleaning Pad, and North SCEP pipeline) are recommended to be closed in place. This closure plan provides the strategy and backup information necessary to support the clean closure of each of the individual components within CAU 93. Analytical data generated during the characterization field work and earlier sampling events indicates the majority of CAU 93 soil and infrastructure is non-hazardous (i.e., impacted primarily with petroleum hydrocarbons)