LOS ALAMOS, N.M. – In an initiative supported by EM, Los Alamos National Laboratory's Corrective Actions Program is addressing high explosive contamination in surface water and groundwater at a location this summer in the forests surrounding the laboratory.

   A high explosive called RDX was machined at the site beginning in the 1950s as part of the laboratory’s weapons development mission. Over time, machining effluent discharged at the site resulted in RDX contamination in soil and water.

   Contamination was removed from the soil during past cleanup operations, but levels of legacy RDX still exist in surface water and groundwater.

   Crews in June began testing to determine how successfully RDX can be removed from groundwater. The test involves pumping water, treating it with activated carbon, and discharging it into the ground. Samples also are taken daily and analyzed internally for RDX.

   In addition to the testing, a technical geophysics study was completed in June to determine the conductivity of the ground around the site. Cables with electrodes were run along the ground throughout the area. The electrodes sent current into the ground to measure the resistance of the underlying geological strata, which will help Los Alamos experts determine the extent of perched intermediate groundwater in the contamination zone and where to drill additional monitoring wells.

   “We have to identify where the groundwater exists in a complex geologic strata in order to remediate the contamination,” said Project Manager John McCann. “These tests are important steps in characterizing contamination at the site and defining the extent of the deep perched intermediate groundwater zone.”