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Title: Corrective Action Decision Document/Closure Report for Corrective Action Unit 554: Area 23 Release Site Nevada Test Site, Nevada, Revision 0

Technical Report ·
DOI:https://doi.org/10.2172/859336· OSTI ID:859336

This Corrective Action Decision Document/Closure Report has been prepared for Corrective Action Unit 554, Area 23 Release Site, located in Mercury at the Nevada Test Site, Nevada, in accordance with the ''Federal Facility Agreement and Consent Order'' (1996). Corrective Action Unit (CAU) 554 is comprised of one corrective action site (CAS): (1) CAS 23-02-08, USTs 23-115-1, 2, 3/Spill 530-90-002. The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation supporting the recommendation for closure of CAU 554 with no further corrective action. To achieve this, corrective action investigation (CAI) activities were performed from January 18 through May 5, 2005, as set forth in the ''Corrective Action Investigation Plan for Corrective Action Unit 554: Area 23 Release Site'' (NNSA/NSO, 2004) and Records of Technical Change No. 1 and No. 2. The purpose of the CAI was to fulfill the following data needs as defined during the data quality objective (DQO) process: (1) Determine whether contaminants of concern are present. (2) If contaminants of concern are present, determine their nature and extent. (3) Provide sufficient information and data to complete appropriate corrective actions. The CAU 554 dataset from the investigation results was evaluated based on the data quality indicator parameters. This evaluation demonstrated the quality and acceptability of the dataset for use in fulfilling the DQO data needs. Analytes detected during the CAI were evaluated against preliminary action levels (PALs) established in the CAU 554 CAIP for total petroleum hydrocarbons (TPH) benzo(a)pyrene, dibenz(a,h)anthracene, and trichloroethene (TCE). Specifically: (1) The soil beneath and laterally outward from former underground storage tanks at CAS 23-02-08 contains TPH-diesel-range organics (DRO) above the PAL of 100 milligrams per kilogram, confined vertically from a depth of approximately 400 feet (ft) below ground surface (bgs). The contamination is confined to 12.5 ft bgs to the subsurface media and laterally within approximately 100 ft of the release. (2) A single soil sample collected from the depth of 99 to 100 ft bgs demonstrated the presence of TCE at a concentration above the PAL. (3) Two soil samples collected from depths of 198 to 199 ft bgs and 380 to 382 ft bgs demonstrated the presence of benzo(a)pyrene at a concentration above the PAL. (4) Two soil samples collected from depths of 240 to 241 ft bgs and 290 to 291 ft bgs demonstrated the presence of dibenz(a,h)anthracene at a concentration above the PAL. Tier 2 final action levels (FALs) were then calculated for these contaminants. The Tier 2 FALs for TCE, benzo(a)pyrene, and dibenz(a,h)anthracene were calculated based on a limited exposure to subsurface contamination scenario, and the Tier 2 FAL for TPH-DRO was established as the U.S. Environmental Protection Agency Region 9 Preliminary Remediation Goal values for the individual hazardous constituents of diesel. The evaluation of TPH-DRO, benzo(a)pyrene, dibenz(a,h)anthracene, and TCE based on the Tier 2 FALs determined that no FALs were exceeded. Therefore, the DQO data needs were met, and it was determined that no corrective action (based on risk to human receptors) is necessary for the site. As a best management practice for the remaining subsurface diesel contamination present at the site, a use restriction was imposed on future site activities that would not allow for future contact of the subsurface contamination. Therefore, the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office provides the following recommendations: (1) No further corrective action for CAU 554. (2) No Corrective Action Plan. (3) A Notice of Completion to the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office is requested from the Nevada Division of Environmental Protection for closure of CAU 554. (4) Corrective Action Unit 554 should be moved from Appendix III to Appendix IV of the Federal Facility Agreement and Consent Order.

Research Organization:
Stoller-Navarro Joint Venture
Sponsoring Organization:
USDOE - National Nuclear Security Administration (NNSA)
DOE Contract Number:
DEAC-5203NA99205
OSTI ID:
859336
Report Number(s):
DOE/NV-1065; TRN: US200603%%331
Country of Publication:
United States
Language:
English