Groundwater Monitoring Report: Monitoring Well MWL-MW4 at Sandia National Laboratories/New Mexico

The Department of Energy/National Nuclear Security Administration (DOE) and Sandia Corporation (Sandia) have performed groundwater monitoring at solid waste management unit (SWMU) 76 at Sandia National Laboratories (SNL). SWMU 76, known as the Mixed Waste Landfill (MWL), is a 2.6-acre site at SNL, 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. DOE and Sandia performed pumping/purging and sampling activities at groundwater monitoring well MWL-MW4 in accordance with recommendations from the New Mexico Environment Department. The results are documented in this report