Sampling and Analysis Instruction for Characterization of 200-XP-1 and 200-ZP-2Spent Granulated Activated Carbon and Filter Elements

摘要

Carbon tetrachloride was found in the unconfined aquifer beneath the 200 WestArea at the Hanford Site in the mid-1980s. Groundwater monitoring indicated that the carbon tetrachloride plume was widespread and that concentrations were increasing. In response to this contamination, removal of carbon tetrachloride from the vadose zone in the 200 West Area was initiated in 1992 as part of the 200-ZP-2 Operable Unit (OU) expedited response action (ERA) (DOE-RL 1991). The ERA uses soil vapor extraction (SVE) systems followed by above-ground vapor treatment on granular activated carbon (GAC). Extracted carbon tetrachloride is collected in the GAC contained in 2.4-m (8-ft)-tall, 1.2-m (4-ft)-diameter carbon-steel canisters. In August 1994, a groundwater pump-and-treat system was installed to treat contaminated groundwater at the 200-ZP-1 OU. The groundwater is treated with an air-stripping unit, followed by vapor-phase GAC polishing, using large carbon-steel canisters similar to those used at the 200-ZP-2 OU. The 200-ZP-1 pump-and-treat system is designed with in-line filters to collect fine particulates present in the groundwater. The particulates collect on filters located in the filter housings. The filter elements are removed from the filter housing and are replaced as needed to maintain system efficiency. The used filters are drained and collected for disposal (which is typically offsite). The spent GAC for the 200-ZP-1 and the 200-ZP-2 OU systems is sent offsite for regeneration and is returned for re-use in the groundwater treatment and SVE systems. This sampling and analysis instruction (SAI) defines the sampling and analysis activities necessary to characterize the GAC and filter media. The data are used to support shipment of the GAC to an offsite commercial treatment, storage, and disposal facility (TSDF) for regeneration and to designate the filter media for disposal.