N3B Los Alamos RDX Project Lead Pat McGuire takes questions Dec. 21 from Regional Coalition of LANL Communities board members during their regular meeting in Espanola as Acting Chief Operating Officer Joe Legare looks on. Photo by Maire O’Neill/losalamosreporter.com

BY MAIRE O’NEILL

Acting Chief Operating Officer for N3B Los Alamos Joe Legare, N3B’s RDX Program Lead Pat McGuire and Chief Scientist Danny Katzman brought members of the Regional Coalition of LANL Communities board up-to-date on the RDX Project at the RCLC’s regular meeting Friday in Espanola.

Legare gave the board an overview of N3B’s structure and current activities as the Legacy Waste cleanup contractor at Los Alamos National Laboratory. Legare noted that there are still some “known unknowns”, the contractor has a very good understanding of the nature and status of contamination across the Lab. He said there’s always competition for funding between the cleanup sites and that historically the funding at Los Alamos has been excellent.

“The best way that I know of to continue that support is to be successful in what we’re doing,” Legare told the board.

McGuire said he hoped board member would come to the conclusion after his presentation that RDX is not within the water supply and that the Department of Energy has an active program to monitor the situation.

McGuire explained that back in the 1950s, facilities were built in the northwest section of the Lab in TA-16 with the purpose of developing and machining high explosives including RDX. During that process he said water was used which came into contact with RDX. That wastewater was then discharged through a pipe from Outfall 260, came into contact with the surface soils and continued to drain down into the Canyon De Valle.

“In the mid-1990s an investigation was conducted and it was determined that RDX was in the surface soils. In the late-1990s, a groundwater investigation was conducted and it determined that RDX was in groundwater. It was below criteria but it still existed in the groundwater. And today we have levels of RDX that are found in spring surface water as well as the groundwater,” McGuire said.

Based on that information he said in the early 2000s, there was a cleanup effort that dealt with the surface soils and approximately 1500 cubic yards of RDX-impacted soils were removed and disposed of off-site.

“There were several different excavations ranging from two feet to about four feet. The one thing they all had in common was at the end of the excavation, confirmation samples were collected and results indicated that the cleanup criteria was met,” McGuire said.

New Mexico Environment Department determined that the surface soil cleanup had been completed but that continued monitoring of the surface water, springs and shallow alluvial wells would continue, he said.

“We actually collect the data throughout the year and an annual report is sent to NMED at the end of September,” he said.

With the completion of the surface soil cleanup the focus then became deep groundwater.

“We needed to understand the nature – the concentrations within the groundwater – and the extent – we had to install monitoring wells. Within the regional aquifer there are currently nine monitoring wells with R-69 being the latest one completed. That gave us a handle on the nature and the extent. Also we needed to understand how RDX moves within the groundwater. So there tracer tests and aquifer tests have been conducted. All of the work that was conducted was with the approval of NMED,” McGuire said.

He noted that there are two major flow regimes in the area – snow melt coming off the Jemez Mountains and infiltrating down into the shallower soils and a deeper system where water from the Jemez Mountain penetrates deeper and eventually into the regional aquifer.

McGuire said in the late 1990s all concentration levels were below the NMED tap water screening level of 7.02 micrograms per liter or parts per billion. With Well R-68 which was installed in 2017 and R-69 which was installed this year, the RDX exceeds the tap water screening level. The R-69 information is preliminary however, having been obtained from a sample taking in a preliminary pumping test. McGuire expects that once N3B starts collecting samples in January 2019, the concentration will go down. He stressed that the distance between those two wells and the public drinking water supply is three miles.

“In between, there are a number of wells screening within the regional aquifer. RDX has never been detected and the detection level is much lower than the 7.02 micrograms. We will continue to monitor as we progress through the process of the RDX campaign,”  McGuire said.

“In August 2019 there is a deep water investigation report due to NMED which will summarize a decade of information that’s been gathered on RD and its nature and extent within the environment. One thing that will be included in this report will be a model,” he said. “This model will help us understand how the RDX will move in the regional aquifer in the future. Based on that information and working collaboratively with NMED, decisions will be made as to whether we go into a remedial evaluations process or not. Ultimately, that document will be submitted to NMED who will review it and comment or approve and we’ll move on from there. No matter what happens we will continue to monitor all the wells for RDX.”

The N3B officials said a five-year baseline plan is being developed with DOE and that after that has been approved they will be in a better position to describe their total project from the perspective of why they sequence work the way they do and what cleanup could be done if there was funding available beyond what that baseline is set to.