IG views groundwater data more favorably

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LANL > Well drilling methods modified after 2005 review

By The Staff

The Department of Energy Inspector General gave the Los Alamos National Laboratory a passing grade when it comes to its characterization wells.

It was the second time in eight years that the DOE IG has examined LANL’s characterization report.

In that 2005 report, the IG said “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.

The report, that was released July 9, said, “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.”

On March 1, 2005, a consent order was agreed to by NMED, DOE and the University of California, which was the prior management company of the lab before Los Alamos National Security LLC., took over in 2006.

The 2005 report said, “we determined that corrective actions had been taken to address the issues with mud rotary drilling identified in our 2005 report. Specifically, the Los Alamos Field Office and New Mexico Environmental Department officials verified that the Hydrogeologic Workplan wells were converted to monitoring wells under the Compliance Order, and that in doing so, certain well screens found to be unreliable were sealed off and no longer used for the collection of radionuclide data.

“Also, instead of using mud rotary drilling techniques, Los Alamos uses various air, potable water and foam techniques for the construction of monitoring wells under the Compliance Order. An example would be the use of foam approximately 100 feet above the aquifer and then the use of air and potable water from that point on. “

Finally, the New Mexico Environmental Department is now responsible for the Los Alamos Characterization Wells Monitoring Program and the requirements of that program as stated in the Compliance Order.”

The July report also took a look at the contamination data.

“We determined that concerns over the reliability of contamination data identified in our 2005 report were addressed by the changes in well drilling processes and the discontinued use of well screens that had been found to be unreliable,” the report said.

“In addition, we noted during our inspection that the groundwater surveillance monitoring program follows well development and purging methods from the Compliance Order, which impact the quality of contamination data. Also, Los Alamos is now required to remove three well volumes of water prior to drawing samples.

“Further, Los Alamos and the New Mexico Environmental Department now perform separate tests using different samples analyzed at different laboratories and the reporting of radionuclide contamination data contains appropriate qualifications on the accuracy and precision of that data.”