NMED News:
A toxic chromium plume from Los Alamos National Laboratory has spread beyond lab boundaries onto Pueblo de San Ildefonso land for the first time, with contamination levels exceeding state groundwater standards, the New Mexico Environment Department (NMED) announced today.
Recent groundwater sampling conducted by the New Mexico Environment Department (NMED) and Los Alamos National Laboratory (LANL) found hexavalent chromium, a toxic and carcinogenic substance, at levels ranging from 53 to 72.9 micrograms per liter (ug/l), depending on the depth sampled. The ground water standard is 50 ug/l.
“These new results are conclusive evidence that the U.S. Department of Energy’s efforts to contain the chromium plume have been inadequate,” said NMED Director of Compliance and Enforcement Bruce Baizel. “While drinking water supplies are safe for now, the U.S. Department of Energy must take immediate and definitive actions to protect drinking water.”
There is no imminent threat to drinking water on Pueblo de San Ildefonso or in Los Alamos County because the chromium plume is not currently near any known private or public drinking water wells.
Long-term ingestion of hexavalent chromium can cause serious health problems, including an increased risk of certain cancers.
The Pueblo de San Ildefonso, New Mexico Office of the State Engineer, and NMED are working together to recommend next steps, including finalizing construction of additional monitoring wells to better track the chromium plume’s migration. Separately, NMED is pursuing civil enforcement actions against the U.S. Department of Energy related to this matter.
From 1956 to 1972, workers at a non-nuclear power plant at LANL periodically flushed hexavalent chromium-contaminated water from the cooling towers into Sandia Canyon. At the time, potassium dichromate was commonly used as a corrosion inhibitor. The water flowed down Sandia Canyon as surface water, penetrated the underlying rock layers and, over time, seeped into the regional aquifer.
LANL stopped releasing chromium-contaminated water in 1972. For the past 53 years, the U.S. Department of Energy has failed to fully remediate the plume leading to its spread under the Pueblo of San Ildefonso. Pueblo leaders authorized the drilling of the monitoring well to improve understanding of the impacts of the contamination from historic LANL operations.