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Contaminant shows up in regional aquifer

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Lab officials think it is an artifact of drilling a monitor well

By Roger Snodgrass

Tucked inside a routine monthly report is the first public disclosure of a potentially troubling new area of contamination in the regional aquifer below Los Alamos National Laboratory.

A cover letter from Los Alamos National Laboratory to the New Mexico Environment Department was dated Aug. 29 and was published by link on a laboratory Web site last week. It calls attention to two elevated readings for the chemical bis(2-ethylhyexyl)phthalate. The samples were found in the water table, some 1,300 feet below the surface, in one of the lab’s new regional monitoring wells R-46.

Associated in numerous instances by the Agency for Toxic Substances and Disease Registry webpage with ammunition plants and explosives, the chemical is also known as DEHP.

“DEHP is everywhere in the environment,” according to ATSDR’s ToxFAQ, “because of its use in plastics, but it does not evaporate easily or dissolve in water easily.”

ATDR associates DEHP with a variety of plastic products, including wall coverings, tablecloths, floor tiles, furniture upholstery, shower curtains, garden hoses and swimming pool liners.

In the introductory paragraph, the fact sheet states, “In animals, high levels of DEHP damaged the liver and kidney and affected the ability to reproduce.”

The letter from the laboratory and federal environmental programs managers to James Bearzi, the state’s hazardous waste bureau chief, followed a meeting on Aug. 12 at which July’s groundwater data was reviewed.

After the meeting, the letter reported the laboratory telephoned the bureau about the findings and followed up with an e-mail on the same day.

Two “unfiltered samples” of the chemical were reported, one 11 times greater than the maximum contaminant level (MCL) standard, which is six parts per billion and the other 16 times greater.

Danny Katzman, LANL’s water stewardship program manager, said this week that the prompt reports are now a requirement under the Consent Order that regulates the laboratory’s environmental cleanup project.

“These are tools to put things on the radar screen,” he said. “They are super conservative so that nothing slips through the cracks.”

The monthly reports on samples showing contaminant concentrations above New Mexico or federal water quality standards were a result of a detection of the pollutant hexavalent chromium in 2004 that went unreported for two years and ultimately led to fines, major changes in laboratory groundwater models, drilling and sampling methods and a large increase in the number of monitoring wells installed or planned.

Katzman said bis-2 had been reported previously to NMED from other locations and was thought to be associated with new wells or the conversion of sampling systems.

 “It pops up early on or goes away after a few rounds, completely or below trace levels,” he said, “It’s not unique to LANL,” he said. “It’s a condition that’s fairly common nationwide.”

Bearzi said the bis-2 reading was disturbing.

“It’s not quite the chromium level of concern, because they told us about this one,” he said.

Despite the near-universal presence of the DEHP contaminant, he noted, the environment department doesn’t think it is a minor matter because of what lies above the detection point, a Cold War dump, known as Material Disposal Area C. MDA C was in operation between 1948 and 1974.

“A witch’s brew of contamination was disposed there when it was in use,” Bearzi said. “Plasticizers that were used with explosives were not uncommon, nor would they be unexpected.”

MDA C would also have organic chemicals that would provide a mechanism for moving the phthalate down into the aquifer and elsewhere into the environment.

“We’re looking very strongly at MDA C as a potential source if not a major source,” he said. “In a week the lab will submit a report on the latest phase of their investigation on MDA C.”

He added, “They’re going to need to do more than just watch it.”

Robert Gilkeson, the registered geologist and citizen groundwater watchdog at LANL and Sandia National Laboratories connected a few more dots in the underground puzzle.

“The R-46 well from which the elevated sample was drawn is located about 1000 ft. east of MDA C as a “nearfield” monitoring well for releases from MDA C,” he wrote in an email Wednesday. “Higher levels of groundwater contamination would be expected at locations close to MDA C.”

Gilkeson was in the midst of preparations for a round of briefings he was asked to provide the Department of Energy Office of Environmental Management this week.

“This is evidence of serious groundwater contamination in the regional aquifer from the old legacy dump, known as MDA C located at (Technical Area 50) and close to the TA-50 liquid waste treatment plant,” Gilkeson concluded, calling for expanding the network of monitoring wells at locations close to all the legacy waste areas at LANL.