BY MAIRE O’NEILL
The Department of Energy’s environmental cleanup project at Middle DP Road was dubbted “odd” and “unique” Wednesday during the virtual Northern New Mexico Citizens Advisory Board meeting.
DOE/EM-LA Director of the Office of Quality & Regulatory Compliance Lee Bishop told the board that “potholing” – using a backhoe to dig some 130 holes –is continuing as legacy waste contractor N3B investigates and removes debris from the Middle DP Road property previously transferred by DOE to Los Alamos County. Bishop said the holes are being dug down to tuff which is as far as they can go, so there’s no debris underneath there.
“We are finding some debris. The soil is not contaminated and some of the debris tends to be contaminated so it’s a different spin on environmental cleanup. A lot of times we’re chasing plumes and distributions. In this one, we’re really looking for 1940s and 1950s rad debris out there to see if it’s contaminated or is environmentally hazardous,” Bishop said. “…We’re slowly moving into the area that we know the original contamination was found. We started on the outside and we started working our way in to where we know there’s contamination, so we’re starting to run into that right now.“
Asked if the soil around the debris also becomes contaminated as well, Bishop said surprisingly, a piece of metal found recently had thousands of decays per minute (DPM).
“We looked at it fixed and loose, and when they smeared it, it was only a few DPM that came off on the smear. For whatever reason, (with) the vintage of the material, all the debris at this time has fixed contamination on it. It’s not a lot of loose contamination. We check the surrounding soil and we are not finding any migration to the soil,” he said. “It’s a very odd cleanup site. I haven’t done one quite like this one before of 40s/50s vintage cleanup of debris. It looks like it’s a shallow landfill where it’s not a surface disposal that just had more dirt piled on top of it. So it’s quite a unique site.”
Bishop said the site is being systematically potholing to find the edges of the disposal site.
“Once we map out the edges, we’ll start chasing the debris and clean out the center. It’s kind of like that old game of Battleship. Empty hole, empty hole, got a hit, got another hit, now we start kind of surmising where the boundaries of this actually are,” he said.
Bishop indicated that a geotechnical crew was deployed to the site to look for magnetic anomalies and that four different technologies had been used to look for anomalies that were detectable near the surface.
Asked about the discovery of a jar of liquid waste that was announced last week in a joint statement by EM-LA and Los Alamos County, Bishop said it was in a 500 ml bottle that looked like a laboratory reagent bottle.
“So it’s your classic chemistry bottle. It was amber in color so we’ve been debating about that and we talked to the Triad folks and they actually have a forensic group – so we’re chatting with them. They want some of the other artifacts. We use that term, not waste artificacts because we haven’t declared it waste yet, to go over and look at some of that as to historic value,” he said. “We’re talking to them to see if they might take it into their internal laboratory and do some forensic work and determine what it might be.
“We expect a little more time to be spent as we’re into the cleanup areas that are out there and we approach them- makping sure we’re doing it right as we move through and get the materials packaged. It’s an investigation that’s going on out there and at times we’re going to find historical materials from the Laboratory operation and it’s all relatively expected but every once in a while we find something that’s not quite the normal of what we would have seem,” Thomson said.
He said it happened a couple of weeks ago when the Los Alamos Fire Department Haz Mat team responded glass bottle was found and a little bit of media coverage was garnered.
“This is all part of our normal protocols for how we would do an investigation at a site. You find something that’s a little bit unknown – you need to approach it cautiously, make sure you’re handling it in the right ways and then make sure you understand what it is as you move forward,” Thomson said. “We looked at the pH on the outside of the bottle which was in the 6-7 range so right arund he pH of water. We still need to get a little more information on the inside of it but each data piece allows us to handle it and make sure we’re handling it in a safe manner. The next phase would be getting it to either an analytical lab or offsite for some disposition. We’re continuing to work that in a nice orderly and consistent process as we work through that item.”
Thomson said N3B has also identified some contaminated debris at DP Road.
“That’s not a surprise either based off the items that were discovered in 2020. We mentioned the metal debris here recently and what we’re doing with the soils. It’s not efficient to just try to take every piece of debris out of these excavations and potholes and segrate, so we do end up with soils getting packaged into the bins with the debris and we continue to over-excavate and chase materials to make sure that we have removed all of that debris and then doing our field measurements on the remaining soils in the hole. We don’t actually measure it in the pothole. We bring the material to the surface, check it with our field instrument, make sure we get good data on it, and then we feel like we’ve completed that cleanup effort,” Thomson said.
Ultimately, he said N3B is going to confirmation sampling of the surrounding soils in those areas as well, to determine if additional excavation is needed or not.
“We’re planning to get it all on the first go, but we don’t want to just plan and hope – it’s come back in and do that confirmatory sampling to make sure that we don’t have anything residual in those soils,” he said.