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Title: Remediation Technologies Screening Report for the Deep Vadose Zone, Hanford's Central Plateau - 12414

Conference ·
OSTI ID:22293651
 [1];  [2]
  1. CH2M HILL Plateau Remediation Company (United States)
  2. U.S. Department of Energy, Richland (United States)

Deep Vadose Zone contamination is a significant issue because it represents a potential source for continued release of contamination to the groundwater and associated receptors. This contamination, which is the result of past waste disposal practices on the Hanford Site Central Plateau, occurs deep in the subsurface and is not easily remediated by typical surface remedies. The Deep Vadose Zone is defined as the sediment below the limit of typical surface-based remedies (such as, excavation or caps), but above the water table. The Central Plateau Deep Vadose Zone begins at a depth of approximately 15 m (50 ft) below ground surface and extends to a depth of approximately 76 m (250 ft) below ground surface. Cleanup of the Deep Vadose Zone is challenging because contamination is difficult to access and expensive to characterize; contaminants occur at different depths and soil types; conventional, surface-based remedies have limited effectiveness; and remedy performance is difficult to predict, test, and monitor. Typically, remedial technologies for Deep Vadose Zone contamination are less developed than for the shallow soil contamination or saturated groundwater contaminants. In addition, few remediation technologies have been tested in the field, and fewer still have been successfully implemented as full remedial actions. These challenges, along with the limited number of potentially applicable remediation technologies, complicate the decision-making process for evaluating and selecting Deep Vadose Zone remedial alternatives. The Deep Vadose Zone remediation technologies pre-screening involved a comprehensive review of potentially applicable technologies for remediating Deep Vadose Zone contamination in the Hanford Site's Central Plateau. The list of remediation technologies was developed from previous Hanford Site studies, science and technology databases, as well as other cleanup projects across the country that have similar conditions. The list of remediation technologies was shared with the public and stakeholders to provide an opportunity to identify additional technologies. From these efforts, 59 technologies that may support future remediation of the Deep Vadose Zone were identified. The initial list of 59 potential technologies were then screened in order to identify viable or potentially viable technologies whose implementation would benefit from further investigation and evaluation during the remedial investigation/feasibility study activities. This approach eliminated five technologies from further consideration because they either would not be ready to support remediation within the next 3 to 5 years or were not applicable for Deep Vadose Zone remediation. Eleven (11) technologies were identified as viable, requiring no further testing or investigation during the RCRA Facility Investigation/Remedial Investigation activities. The remaining 43 potentially applicable technologies were identified as requiring additional testing or investigation to determine whether they should be considered further in the selection of a remedial alternative for the 200-DV-1 Operable Unit. The results of this pre-screening effort will be used to plan and scope the appropriate field investigation, treatability study, and feasibility study tasks during development of the 200-DV-1 Operable Unit Work Plan. (authors)

Research Organization:
WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
OSTI ID:
22293651
Report Number(s):
INIS-US-14-WM-12414; TRN: US14V1307115175
Resource Relation:
Conference: WM2012: Waste Management 2012 conference on improving the future in waste management, Phoenix, AZ (United States), 26 Feb - 1 Mar 2012; Other Information: Country of input: France; 35 refs.
Country of Publication:
United States
Language:
English