Sandia National Laboratories (SNL) is a multi-program laboratory managed and operated by Sandia Corporation (Sandia), a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s (DOE’s) National Nuclear Security Administration under contract DE-AC04-94AL85000.

SNL is located on Kirtland Air Force Base immediately southeast of Albuquerque, New Mexico. Solid waste management unit (SWMU) 76, known as the Mixed Waste Landfill (MWL), is a 2.6-acre site at SNL. 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 waste burial is approximately 25 feet below the ground surface. Groundwater occurs approximately 500 feet below the ground surface at the MWL.

This folder contains a collection of documents related to corrective action at SWMU 76.


SWMU 76 and other SWMUs are listed in the Hazardous Waste Permit (Permit) for SNL. Corrective action is a process that consists of several steps:

  • Initial identification and assessment of potential SWMUs.
  • Investigation to characterize each SWMU (i.e., collect the data necessary to determine the nature and extent of any releases of wastes or constituents), and to evaluate whether wastes or constituents that are present or may have been released pose an unacceptable risk to human health and the environment.
  • Evaluation of corrective measures alternatives or remedies (e.g., methods for containing or cleaning up releases, if necessary).
  • Selection of measures and remedies by the New Mexico Environment Department (NMED).
  • Implementation and completion of the selected measures and remedies.
  • Maintenance of controls after completion of the selected measures and remedies, where appropriate.

DOE and Sandia have implemented corrective measures at SWMU 76 and NMED issued a Certificate of Completion on October 8, 2014. On January 8, 2014, NMED approved a long-term monitoring and maintenance plan (LTMMP) for SWMU 76. DOE and Sandia are implementing the approved LTMMP, maintaining the controls established through the corrective measures.


On October 20, 2014, DOE and Sandia submitted a request for a Class 3 modification to the Permit, requesting that NMED designate SWMU 76 as approved for Corrective Action Complete status.

DOE and Sandia presented information about SWMU 76 in poster format at a meeting on Tuesday, November 18, 2014 at the Manzano Mesa Multigenerational Center in Albuquerque. Posters and handouts from the meeting are included in this collection of documents.

A public comment period associated with this request for a Class 3 permit modification began on October 20 and closed on January 5, 2015. All comments submitted to DOE and Sandia during the comment period were forwarded to NMED on February 19, 2015. The compiled comments are included in this collection of documents.


Additional information regarding SWMU 76 may also be available from the NMED Hazardous Waste Bureau at

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