LANL Updates Public on Chromium Contamination
Los Alamos National Laboratory (LANL) environmental officials recently held a public groundwater meeting on the status of their investigation into chromium contamination as well as to discuss the quality of their groundwater well network.
LANL has not gained any new knowledge about the size, extent or movement of the chromium plume in the regional aquifer or its threat to drinking water. However, LANL has investigated the chromium travel path to groundwater and recently began drilling two new wells to investigate the contamination.
Elevated levels of toxic hexavalent chromium were first detected in a regional aquifer well in January of 2004. LANL reported the detections to the New Mexico Environment Department (NMED) two years later in December of 2005. During that time the detected chromium levels nearly doubled from 270 parts per billion (ppb) to 405 ppb. Since then the levels at that well have fluctuated around 400 ppb. The New Mexico Drinking Water standard is 50 ppb.
LANL announced that during their chromium investigation they detected the presence of molybdenum along the assumed travel pathway. First chromium and later molybdenum was used as corrosion inhibitor at LANLŐs Omega West Reactor and both were discharged into the canyons. Its presence indicates that the travel time for a fast moving contaminant from canyon bottom to the regional aquifer may be between 25 and 30 years.
Molybdenum is a metal, which can be toxic when ingested at high levels. Molybdenum blocks the absorption of zinc and copper and has been found to irritate the eyes, nose and throat, as well as cause diarrhea, weight loss, and liver and kidney damage.
In order to investigate the extent and movement of the chromium plume, LANL has begun to drill a new pair of characterization wells. These wells are located between the detections of chromium and a Los Alamos County well, PM-3, which is the primary drinking water well for the community of White Rock. In addition to gathering information, the wells will serve as a sentry for PM-3. Drilling began on March 30 and will be completed in about two months. The first results of samples from those wells will be available by early August.
This pair of wells is being drilled without the use of drilling fluids that have been the subject of contention. Community groups have objected to the use of these fluids because of their well-documented properties to mask the presence of contaminants. At the meeting, Concerned Citizens for Nuclear Safety publicly thanked LANL for refraining from the use of drilling fluids in these wells.
NMED recently questioned the validity of LANLŐs groundwater well network, in part because of the persistent use of these fluids, and issued new orders. NMED imposed an accelerated timeline and required LANL to evaluate all wells in the network. However, LANL did not address theses orders at the meeting.
James Bearzi, chief of the stateŐs Hazardous Waste Bureau, said that the state remains concerned that LANL will not have the necessary system in place to determine the best method of cleanup for legacy waste dumps.
Bearzi said, "We need groundwater detection monitoring and we donŐt have it now."
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