Los Alamos National Laboratory officials, from right, Doug Hintze, Environmental Management manager, Pat McGuire, N3B Los Alamos RDX Project Manager, and Danny Katzman, N3B Technical Manager brief the Los Alamos County Council Feb. 5 during a work session in White Rock. Photo by Maire O’Neill/losalamosreporter.com
BY MAIRE O’NEILL
N3B Los Alamos RDX Project Manager Pat McGuire gave an overview of the RDX project to Los Alamos Councilors Tuesday evening at their work session in White Rock.
Also present were Los Alamos National Laboratory Environmental Management manager Doug Hintze, N3B’s Technical Manager Danny Katzman, and several other N3B officials.
Following his presentation on the background and prior activities on the project, McGuire said the monitoring plan is to continue to sample not only the wells that are in the RDX area but also those wells between there and the County’s public water supply wells including the water supply wells themselves.
McGuire said in August N3B will be submitting a Deep Groundwater Investigation Report which will assess whether or not RDX contamination has been sufficiently characterized. He said in addition there will be a numerical model which will allow N3B to assess the potential for the long-term migration of RDX into the regional aquifer and show what the footprint will look like in the regional aquifer in five, 10, 15, 20 years. He told the Council that the model will tell if remediation is necessary and that if it is necessary, a plan will be developed and proposed.
“Regardless of what happens, long-term monitoring will continue and it will ensure the protection of the water supply,” McGuire said.
He said the review of the investigation report by New Mexico Environment Department would likely take about six months and in February 2020 a decision would be made to either go into long-term monitoring or go into a Corrective Measures Evaluation to look at and select remedial alternatives. That would be due to NMED in August 2020 and when NMED decides how to proceed, a Corrective Measures Implementation Plan with that design would have to be submitted to NMED in 2021.
Council Vice Chair Pete Sheehey said that if the water in the vicinity of the contamination moves 20 to 40 feet a year, he calculated it would take roughly 100 years to reach the County water supply wells and asked if that was a reasonable estimate. Katzman responded that that would be one of the things that will come out of the investigation report.
“If there’s any indication it could migrate, we’re not going to let it get anywhere near those water supply wells. Your estimate would be accurate if we were to leave it alone and never touch it,” he said. He said N3B and NMED will be looking at the migration issues to make sure that if there was any indication of RDX nearing the water supply wells, action would be taken to make sure it never reached them.
Sheehey asked if there was a process similar to the one being utilized for chromium mitigation that could be used to remove RDX.
McGuire said there could be several alternatives for RDX and that one would be a pump and treat scenario He said that RDX is also biodegradable and that alternative could be looked at to see if there was anything that could be done in situ.
Councilor David Izraelevitz asked how long “long-term” monitoring would continue. Katzman responded that there is no formal statutory definition,
“Sometimes after we close a site there will be post-closure monitoring. Typically that’s 30 years to make sure that the performance you expected out of your remedy is actually robust and holding true. In this kind of program the long-term monitoring will be guided by whatever the need is,” Katzman said.
He said there’s actually a branch of the Department of Energy that’s Legacy Management that will typically conduct those long-term obligations in perpetuity.
“In this situation where there’s a natural dilution by degradation there may be a point at which you see that the concentration trends are beginning to decline below levels that would be of concern and below the monitoring level obligation,” Katzman said.
Izraelevitz asked who would make those decisions and Katzman said a long-term monitoring plan would have to be put forward and NMED would have to approve it. Izraelevitz also asked how accurate are the models planned for the project.
“A model is only as good as the information you put into it so the more robust your data set is, the better off you are.” Katzman said. “In environmental work like this there are no absolutes – when you’re talking about something that’s 1300 feet below the ground surface in an aquifer that you never perfectly understand.” Katzman said he would provide the information on the grout to the Council.
Councilor Antonio Maggiore asked about the grouting process discussed in the presentation and what type of grout was used. He also asked about the edge of the contaminated area as reflected in presentation slides. Katzman said he would provide the information on the grout to the Council. With regard to the contamination boundary, he said the groundwater flow direction is to the northeast and showed on a map where the wells are that show some control and wells that show some sort of detection of RDX. He said the edge shown on the map is an approximation because when you are talking about a depth of 1,300 feet, the depiction is not intended to be perfect.
Councilor Randy Ryta asked besides chromium and RDX what other compounds had been found. Katzman responded that there have been minor detections of a couple of other associated compounds but that they are all below regulatory level.
Asked about the mass of RDX estimated to be present, Katzman said 1500 to 3600 kg total.
“That mass and the uncertainty about how much RDX is down there is probably the most important element of the model, trying to understand and represent how that could change over time,” he said.
Katzman said for something to contaminate the groundwater at such great depths, there has to be three pieces in place.
“There has to be a contaminant that’s mobile in the environment, there has to be a whole lot of it, and there has to be that hydraulic driver that keeps pushing it. RDX and chromium are the two places where we see those three conditions come together,” he said.
Council Chair Sara Scott asked about lessons learned from other places where RDX contamination is an issue. Katzman said the LANL is plugged in within the rest of the DOE complex. He said there are always pros, cons and pitfalls in all the types of strategies being used.
“We’re trying to contemplate all of those before implementing anything here. The Corrective Measures Evaluation document will bring in industry knowledge, technologies, a technology screening process. Some strategies might not be feasible here because our groundwater chemistry is different,” he said.
Katzman said it is not uncommon, especially at great depths like at LANL, for a remedy to require 10 to 20 years or even longer. He said there are sites around the country where people have been working for 40 years or more.
“We certainly don’t want to find ourselves in that situation but one of the important principles in approaching something like that is to first protect all your points of expulsion. We have the good fortune that we have institutional control on the Laboratory site in that someone can’t just come up here and punch a well where we lose institutional control,” he said.
To read a report on Katzman’s presentation on RDX to the Voices of Los Alamos follow this link: https://losalamosreporter.com/2019/02/02/katzman-addresses-rdx-and-chromium-projects-at-voices-of-los-alamos-meeting/