N3B gives cleanup update

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By Tris DeRoma

The chief scientist of water programs at N3B, the contractor in charge of cleaning up decades-old contamination sites at the Los Alamos National Laboratory, said significant progress is being made in cleaning up a chromium plume at Mortandad Canyon.


N3B Scientist Danny Katzman made his remarks at a Voices of Los Alamos meeting at the Unitarian Church of Los Alamos earlier this month.

While a permanent solution to cleaning the plume is a few years off, according to the project’s official timeline, Katzman said they’re starting work this year on stopping the plume from expanding past the lab’s boundary with San Ildefonso Pueblo,  and also into Los Alamos County’s drinking water well field.  

According to Katzman, one of the ways they hope to accomplish that is by converting one of six injection wells they have along the plume’s boundary into an extraction well. Katzman said computer modeling showed them the new extraction well would help reduce the footprint of the plume over time, and keep the chromium from migrating into a nearby county drinking water well.

“If it works the way we modeled it, it will do its work to tighten up the footprint of the plume, keep it away from very important boundaries and water supply wells while we figure out what we’re going to do to clean it up,” Katzman said.

The chromium deposit was formed when a nearby power plant drained cooling water from its towers into the canyon from 1956 to 1972. The chromium, known as chromium 6, was used as a pipe corrosion inhibitor. It is harmful to humans.

The plume, which is about 1 mile long, half a mile wide and 50-feet deep, sits over a layer of rock over a regional aquifer the county draws drinking water from.

Ever since the discovery of the plume in 2005, county, state and federal agencies have been monitoring the chromium levels in the drinking water every year.

Katzman said they’ve seen significant progress in reducing the actual amount of chromium in the plume.

“In just six or seven months of pumping, we’ve seen dramatic decreases in concentrations of chromium…sample injection wells four and five, they are essentially absent of chromium other than naturally occurring chromium concentrations,” Katzman said.

Alejandra Wernicky, who was in attendance at the meeting, said she was very pleased with the new developments.

“I think we have good information about the measures they are taking to prevent the chromium from expanding and reaching the boundaries of the county’s water supply and the pueblo. It was very interesting,” Wernicky said.

Jean Steward, who also attended the meeting, said it was impressive that N3B was going to finally be able to move the plume away from sensitive areas.

“You know what they say, Mother Nature speaks first and last, and we’re actually having an impact. To actually have some control over that is exciting,” Steward said.

Katzman also talked about the RDX contamination at Tech Area 16, left over from a site where high explosives were manufactured.  

The DOE EM Department in Los Alamos has worked since 2015 on a plan for cleaning up a decades-old, concentration of RDX, a chemical used by the Los Alamos National Laboratory in the manufacturing high explosives.

The plume was discovered on the property in the early 2000s.

The plume of RDX is located under Tech Area 16, located in the southwestern corner of the lab.

Amounts of RDX have reached the regional aquifer, but has not entered the county’s water supply.  

The closest county drinking water well field is approximately three miles away. According to Katzman, N3B is in the latter stages of determining the extent of the spill and the amount that’s in the aquifer.

N3B plans on submitting a report of its findings this August to the New Mexico Environment Department.

The department then will determine what actions to take.

Earlier this year, monitoring at Well R-68 showed RDX levels between 15 and 20 parts of chromium per billion. The accepted the New Mexico Tapwater Screening Level is 7.2 parts per billion. N3B is still waiting on results from a well it just drilled, called Well R-69.