Thursday, July 25, 2013

Ground Water Monitoring Wells at LANL

The Department Of Energy Office of the Inspector General recently issued a report about alterations made to the methodology in use at Los Alamos National Laboratory for installing characterization and monitoring wells. These wells, of which there are 32 in number, have been deemed necessary to determine the type and extent of groundwater contamination by detritus from the nuclear weapons program. (See IG Report No. INS-L-13-05, dated 9 July, 2013, available on the DOE's website.)

 The installation of characterization and monitoring wells into the regional aquifer underlying LANL has been a contentious topic for the past ~10 years. At issue has been the use of an apparently inappropriate technology for the drilling of these wells; specifically, the use of the mud rotary drilling method. It has now been admitted by LANL authorities that the use of drilling muds to facilitate the drilling process, a standard practice in some parts of the well-drilling industry, was probably misguided, since residual muds left in the well bore acted to obscure the presence of chemical and radioactive contaminants in the well water.

 This defeated the whole purpose of the characterization and monitoring well program, which was to detect the type and measure the extent of groundwater contamination by chemical toxins and radioactive poisons from the nuclear weapons program.

 The IG's report points out that LANL no longer uses the mud enhanced drilling methodology, having substituted air and/or drilling foam for mud. Meanwhile, wells that have been drilled with mud have been, to some extent and where possible, rehabiliated. Hence, the IG's report says that " ... steps had been taken to ensure that data derived from monitoring wells is more reliable."

 What the IG's report does not make clear is that a large fraction of the wells that are now in place at LANL have been drilled with mud, and that the rehabilitation of such wells is itself a fraught process.

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