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Title: Corrective Action Decision Document/ Closure Report for Corrective Action Unit 556: Dry Wells and Surface Release Points, Nevada Test Site, Nevada with Errata Sheet, Revision 0

Technical Report ·
DOI:https://doi.org/10.2172/939196· OSTI ID:939196

This Corrective Action Decision Document (CADD)/Closure Report (CR) has been prepared for Corrective Action Unit 556, Dry Wells and Surface Release Points, located at the Nevada Test Site, Nevada, in accordance with the Federal Facility Agreement and Consent Order (FFACO, 1996; as amended February 2008). Corrective Action Unit (CAU) 556 is comprised of four corrective action sites (CASs): • 06-20-04, National Cementers Dry Well • 06-99-09, Birdwell Test Hole • 25-60-03, E-MAD Stormwater Discharge and Piping • 25-64-01, Vehicle Washdown and Drainage Pit The purpose of this CADD/CR is to provide justification and documentation supporting the recommendation for closure of CAU 556 with no further corrective action. To achieve this, corrective action investigation (CAI) activities began on February 7 and were completed on June 19, 2008, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 556: Dry Wells and Surface Release Points, Nevada Test Site, Nevada (NNSA/NSO, 2007). The purpose of the CAI was to fulfill the following data needs as defined during the data quality objective (DQO) process: • Determine whether contaminants of concern (COCs) are present. • If COCs are present, determine their nature and extent. • Provide sufficient information and data to complete appropriate corrective actions. The CAU 556 data were evaluated based on the data quality assessment process, which demonstrated the quality and acceptability of the data for use in fulfilling the DQO data needs. Analytes detected during the CAI were evaluated against appropriate final action levels (FALs) to identify the COCs for each CAS. The results of the CAI identified COCs at one of the four CASs in CAU 556 that required the completion of a corrective action. Assessment of the data generated from investigation activities conducted at CAU 556 revealed the following: • Corrective Action Sites 06-20-04, 06-99-09, and 25-64-01 do not contain contamination at concentrations exceeding the FALs. • Polychlorinated biphenyl (PCB) contamination above the FAL was identified in the surface and/or shallow subsurface soils at the outfall and around Catch Basin 2, and in soils contained within the catch basins and the manhole at CAS 25-60-03. A corrective action of close in place with a soil removal action and use restriction (UR) was completed at CAS 25-60-03. The PCB-contaminated soils were removed from the outfall area and around Catch Basin 2, and disposed of at a Nevada Test Site landfill as part of a removal action. The catch basins and the manhole were sealed shut by filling them with grout. The end of the outfall pipe was plugged using grout, covered with soil, and the area was regraded. A UR was applied to the entire stormwater system at CAS 25-60-03, which includes the three catch basins, manhole, and associated piping. No further action is the corrective action for CASs 06-20-04, 06-99-09, and 25-64-01. The liquids in the test holes at CAS 06-99-09 were removed for disposal and the features were filled with grout as a best management practice. The drainage pipe between the vehicle washdown pad and the drainage pit at CAS 25-64-01 was sealed at each end as a best management practice. The corrective actions were evaluated on technical merit focusing on performance, reliability, feasibility, safety, and cost. They were judged to meet all requirements for the technical components evaluated. The corrective actions meet all applicable federal and state regulations for closure of the site and will reduce potential exposure pathways to the contaminated media to an acceptable level at CAU 556. Therefore, the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office provides the following recommendations: • Maintain a UR for the entire stormwater drainage system (i.e., three catch basins, one manhole, and associated piping) at CAS 25-60-03. • No further corrective action for CAU 556. • 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 556. • Corrective Action Unit 556 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
DOE Contract Number:
DEAC5203NA99205
OSTI ID:
939196
Report Number(s):
DOE/NV-1285
Country of Publication:
United States
Language:
English