SWMU 76 - Mixed Waste Landfill - Corrective Action

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The Department of Energy/National Nuclear Security Administration (DOE) and Sandia Corporation (Sandia) implemented corrective measures at solid waste management unit (SWMU) 76 in accordance with the requirements of the Permit; an April 2004 Compliance Order on Consent between NMED, DOE, and Sandia; and the plans approved by the New Mexico Environment Department (NMED). On January 8, 2014, NMED approved a long-term monitoring and maintenance plan (LTMMP) for SWMU 76. DOE and Sandia have implemented the approved LTMMP, maintaining the controls established through the corrective measures. SWMU 76, known as the Mixed Waste Landfill (MWL), is a 2.6-acre site at Sandia National Laboratories, located on Kirtland Air Force Base immediately southeast of Albuquerque, New Mexico. Radioactive wastes and mixed wastes (radioactive wastes that are also hazardous wastes) were disposed of in the MWL from March 1959 through December 1988. The maximum depth of burial is approximately 25 feet below the ground surface. Groundwater occurs approximately 500 feet below the ground surface at the MWL. In 2014, DOE and Sandia installed three additional wells to collect samples of vapor in the soil beneath SWMU 76. Volatile organic compound vapors are present in the air in the vadose zone, which is the 500-foot-thick zone of unsaturated soil between the ground surface and the groundwater. Sanples were collected in September from all five of the soil-vapor monitoring wells at SWMU 76. The samples were analyzed for various volatile organic compounds as specified in the LTMMP. This document contains the preliminary results of these samples. These results will be included in the Annual LTMMP Report that will be submitted to NMED on or before June 30, 2015. 17 pages

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Sandia National Laboratories


soil-vapor, monitoring, vadose zone, preliminary results, volatile organic compounds, Corrective Action Complete, LTMMP, long-term monitoring and maintenance, SWMU, solid waste management unit