July 9, 2013
Follow-up Inspection on Characterization Wells at Los Alamos National Laboratory
Since the early 1940's, the Los Alamos National Laboratory (Los Alamos) has conducted experimental research on the development of nuclear weapons and explosive materials. These activities have resulted in the generation and disposal of a variety of hazardous, radioactive, and solid wastes. In 1998, Los Alamos developed a workplan that established the basis for characterizing the hydrogeologic system beneath the facility. Implementation of the workplan required the installation of 32 regional aquifer wells, commonly referred to as characterization wells.
In our September 2005 report on Characterization Wells at Los Alamos National Laboratory, (DOE/IG-0703), we noted that the use of mud rotary drilling methods during well construction was contrary to specific constraints established in Resource Conservation and Recovery Act guidance. We also noted that muds and other drilling fluids that remained in certain wells after construction created a chemical environment that could mask the presence of radionuclide contamination and compromise the reliability of groundwater contamination data.
Our follow-up inspection found that Los Alamos had taken action designed to improve the management of its characterization well program. Specifically, we noted that Los Alamos no longer uses mud rotary drilling methods during well construction, and appropriate steps have been taken to ensure data derived from monitoring wells is reliable. Additionally, we found that responsibility for the monitoring well program had been transferred to the New Mexico Environmental Department.