POST-CLOSURE INSPECTION AND MONITORING REPORT FOR CORRECTIVE ACTION UNIT 112: AREA 23 HAZARDOUS WASTE TRENCHES, NEVADA TEST SITE, NEVADA; FOR THE PERIOD OCTOBER 2003 - SEPTEMBER 2004
Corrective Action Unit (CAU) 112, Area 23 Hazardous Waste Trenches, Nevada Test Site (NTS), Nevada, is a Resource Conservation and Recovery Act (RCRA) unit located in Area 23 of the NTS. This annual Post-Closure Inspection and Monitoring Report provides the results of inspections and monitoring for CAU 112. This report includes a summary and analysis of the site inspections, repair and maintenance, meteorological information, and neutron soil moisture monitoring data obtained at CAU 112 for the current monitoring period, October 2003 through September 2004. Inspections of the CAU 112 RCRA unit were performed quarterly to identify any significant physical changes to the site that could impact the proper operation of the waste unit. The overall condition of the covers and facility was good, and no significant findings were observed. The annual subsidence survey of the elevation markers was conducted on August 23, 2004, and the results indicated that no cover subsidence4 has occurred at any of the markers. The elevations of the markers have been consistent for the past 11 years. The total precipitation for the current reporting period, october 2003 to September 2004, was 14.0 centimeters (cm) (5.5 inches [in]) (National Oceanographic and Atmospheric Administration, Air Resources Laboratory, Special Operations and Research Division, 2004). This is slightly below the average rainfall of 14.7 cm (5.79 in) over the same period from 1972 to 2004. Post-closure monitoring verifies that the CAU 112 trench covers are performing properly and that no water is infiltrating into or out of the waste trenches. Sail moisture measurements are obtained in the soil directly beneath the trenches and compared to baseline conditions for the first year of post-closure monitoring, which began in october 1993. neutron logging was performed twice during this monitoring period along 30 neutron access tubes to obtain soil moisture data and detect any changes that may indicate moisture movement beneath each trench. Soil moisture results obtained to date indicate that the compliance criterion of less than 5% Residual Volumetric Moisture Content was met. Soil conditions remain dry and stable beneath the trenches, and the cover is functioning as designed within the compliance limits.
- Research Organization:
- BECHTEL NEVADA
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- DE-AC08-96NV11718
- OSTI ID:
- 901900
- Report Number(s):
- DOE/NV-1030; TRN: US0702778
- Country of Publication:
- United States
- Language:
- English
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Annual Report RCRA Post-Closure Monitoring and Inspections for CAU 112: Area 23 Hazardous Waste Trenches, Nevada Test Site, Nevada, for the period October 2000-July 2001
Annual Report RCRA Post-Closure Monitoring and Inspections for Corrective Action Unit 112: Area 23 Hazardous Waste Trenches, Nevada Test Site, Nevada