A decades-old toxic chromium plume from Los Alamos National Laboratory has migrated onto San Ildefonso Pueblo land, the New Mexico Environment Department announced Thursday.
There is “no imminent threat to drinking water” on the pueblo or in Los Alamos County, the Environment Department said in a statement.
But the new groundwater testing results “are conclusive evidence that the U.S. Department of Energy’s efforts to contain the chromium plume have been inadequate,” said Bruce Baizel, the Environment Department’s director of compliance and enforcement.
“While drinking water supplies are safe for now, the U.S. Department of Energy must take immediate and definitive actions to protect drinking water,” Baizel said in a statement.
The Department of Energy did not immediately respond to a request for comment Thursday afternoon.
Hexavalent chromium is a known carcinogen that, when ingested in drinking water, can harm the liver, kidneys and reproductive systems and, some research suggests, can cause stomach cancer.
Lab workers between 1957 and 1972 dumped water from an old power plant’s cooling towers that had been funneled through steel pipes laced with hexavalent chromium into Sandia Canyon. From there, the water traveled several miles to Mortandad Canyon and pooled about 1,000 feet underground in a huge plume the lab discovered in 2005.
The plume’s boundary has been fuzzy — a 15-member independent review team that studied the chromium plume released a report early this year stating a “small portion” of the plume had possibly already reached or passed into San Ildefonso Pueblo.
The recent groundwater sampling on pueblo land found hexavalent chromium at levels ranging from 53 to 72.9 micrograms per liter, according to the news release — above the groundwater standard of 50 micrograms per liter.
The pueblo, the State Engineer’s Office and the Environment Department are working together, according to the news release, to recommend steps including “finalizing construction of additional monitoring wells to better track the chromium plume’s migration.”
Additionally, the Environment Department “is pursuing civil enforcement actions against the U.S. Department of Energy related to this matter,” the release states.