Justification for Class 3 Permit Modification, Corrective Action Complete with Controls, Solid Waste Management Unit 76, Mixed Waste Landfill, Sandia National Laboratories/New Mexico, EPA ID Number NM5890110518 Volumes I through VIII

Volume/pages: I/858. II/420. III/556. IV/1128. V/848. VI/1110. VII/914. VIII/866.The Department of Energy/National Nuclear Security Administration (DOE) and Sandia Corporation (Sandia) are submitting a request for a Class 3 Modification to Module IV of Hazardous Waste Permit NM5890110518-1 (the Permit). DOE and Sandia are requesting that the New Mexico Environment Department (NMED) designate solid waste management unit (SWMU) 76 as approved for Corrective Action Complete status. NMED made a preliminary determination in October 2014 that corrective action is complete at this SWMU. 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 meximum depth of burial is approximately 25 feet below the ground surface. Groundwater occurs approximately 500 feet below the ground surface at the MWL. DOE and Sandia have implemented corrective measures at 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 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. The permit modification request consists of a letter with two enclosures: 1. A brief history or corrective action at SWMU 76 2. An index of the supporting documents that comprise the justification for the permit modification request. The supporting documents are included in an 8-volume set: Justification for Class 3 Permit Modification for Corrective Action Complete With Controls, Solid Waste Management Unit 76, Mixed Waste Landfill.Department of Energy (DOE