BY MAIRE O’NEILL
In 2005, initial groundwater samples detected hexavalent chromium in excess of the New Mexico drinking water standard in the regional aquifer beneath Sandia and Mortandad canyons at Los Alamos National Laboratory (LANL). Given this unexpected discovery, Department of Energy (DOE) Environmental Management initiated several major actions including the installation of monitoring wells (based on the depth of the regional aquifer, these wells are drilled approximately as deep as the Empire State Building is high) and piezometers, which were both used to delineate the three-dimensional extent of the chromium impact to the regional aquifer in most directions. Studies were undertaken to understand the aquifer matrix and to protect potential migration pathways for the chromium.
Based on these early initiatives, it was projected that the plume might cross the LANL boundary onto Pueblo de San Ildefonso land. In response, an Interim Measures treatment system was designed, installed and put into operation. Additionally, pilot tests have been conducted to test different potential permanent remedial strategies.
Seventeen years after the identification of the plume of chromium, the DOE Environmental Management Los Alamos (EM-LA) Field Office will submit an updated Chromium Interim Measures and Characterization Work Plan to the New Mexico Environment Department (NMED) this month. Over the last couple of years, NMED, which has been involved all along with the plan to deal with the plume, has spoken out publicly indicating its dissatisfaction with the pace of DOE cleanup of the plume and other LANL legacy waste under the terms of the 2016 Consent Order. NMED last year filed suit on the issue.
The Los Alamos Reporter sat down with DOE/EM-LA Field Office Manager Michael Mikolanis for a long discussion on the chromium plume and what he calls the DOE’s “bias for action” for moving from the interim measure to the final remedy for the plume.
Mikolanis noted that in FY2021, DOE and NMED were not successful in negotiating scope for the milestones and targets for cleanup under Appendix B of the 2016 Consent Order. The difference of opinion was on the schedule for when the deliverables would be provided by knowledge of what it would take to complete the proposed work. NMED did not agree with the schedule, however all 13 proposed deliverables were completed within FY2021.
“We delivered on the schedule that we proposed. We just couldn’t agree to deliver it earlier because if we committed to an earlier date and couldn’t meet it, then it looks like the DOE is not doing its work or meeting its timetable.” Mikolanis said.
Appendix B is not what drives the cleanup work DOE intends to do, he said, adding that he views it as a tool for accountability to the state and the residents of New Mexico.
“Appendix B captures parts of the work that we’re doing – the things that the state says are important enough that they want to hold us accountable for in an enforcement space if we don’t deliver that work on time. Appendix B doesn’t drive the work. The Consent Order defines the work that needs to be done but our work plans, my contract with my corporate partners at N3B, is what makes the work happen. We share the scope we’re doing. We ask NMED what pieces of the scope they want to pull out and make targets and milestones to hold us accountable in enforcement space under the Consent Order,” Mikolanis said.
The Consent Order doesn’t cover all cleanup work by DOE such as transuranic waste shipment or environmental remediation work expectations and Mikolanis believes DOE would continue with cleanup even without a Consent Order in place.
“I would disagree with a characterization that if it wasn’t for the Consent Order DOE would pull their foot off the gas pedal,” he said.
DOE has estimated that cleanup at LANL will be completed by 2036 and that is what DOE is reporting to the state, but Mikolanis thinks there are going to be some real challenges in meeting the 2036 date moving forward.
“One challenge is going to be that our assumptions in what we have in the contract with our cleanup partner N3B assumes ‘cap and cover’ for the Material Disposal Areas. What I’ve heard since I’ve been here from the Los Alamos County Council, elected officials in Santa Fe, from NMED and in my engagements with the community is there are some very vocal voices that don’t like ‘cap and cover’. There are some who’ll go all the way from dig up every cubic centimeter and ship it to someone else’s back yard, to targeted retrieval, to some support for ‘cap and cover’,” he said.
Mikolanis said what he expects to come out of the EM-LA’s Strategic Vision is that some of the planning assumptions of implementing solely ‘cap and cover’ will be revisited and that is likely to impact the 2036 date.
“It will reflect the desire of the stakeholders and will put NMED in a better position to defend something if it’s ‘cap and cover’ because it’s reflective of what the stakeholders have told us. NMED is going to be able to watch that whole process and we’ve had extensive discussions with them about what we’re doing,” he said.
Another data point that challenges the 2036 date is the resources the state has provided to NMED to support the pace of work DOE needs to accomplish that date. Although recent comments by NMED officials indicate that NMED is pushing DOE, Mikolanis says if DOE ramps up the pace of activity it’s going to be very important that the state can review the deliverables that are turned in, such as work plans and corrective measures evaluations (CMEs), and turn them around in time to be able to support the DOE schedules.
‘I’m not being critical of NMED; I know they’re working hard to support us. In fact, we receive a lot of their subject matter expert time working issues related to the chromium plume etc. but it will be very important for the state of New Mexico to provide NMED with the resources necessary in order to keep up with us as we work technical issues. The 2036 date will absolutely be unachievable if we get into the practice of working a solution and tossing it over the fence – the regulator looks at it and says, ‘No -wrong color rock’ and tosses it back again. It takes regulator engagement throughout the process to make sure DOE is headed down a path NMED is going to accept,” Mikolanis said.
He said otherwise things go back and forth, which is inefficient for DOE because they’re doing re-work and it’s inefficient for the state’s resources because they’re having to look at the products two or three times. He said he will continue to meet with NMED leadership and hopes that going forward the two entities will move ahead in nailing down the resources they will need and the pace to work at.
“We’re being very transparent about our work plans, the resources that we’re bringing to bear in different areas to help NMED plan to have the right people with the right expertise at the right time in the right numbers to be able to do that interim engagement with us instead of that engagement at the end when it becomes very inefficient. NMED recognizes that in order to drive cleanup as fast as possible for the residents of New Mexico, we need to sync up the scopes on that end. There’s a lot of work to be done there still and so far the engagement has been very positive. I’m getting good support trying to work some of these issues with the deliverables in Appendix B this year,” Mikolanis said.
Mikolanis addressed recent comments by NMED that indicate that they are not happy with the amount of chromium already removed from the plume. A total of 160,000lbs of chromium was released into the canyon but not all of it has reached the aquifer, he said.
“About 40 percent is bound up on the surface in the wetlands where it chemically binds with organics, soils and sediments. We estimate that between 9,000 and 13,000lbs, less than 10 percent, has made it to the aquifer,” he said.
And that is the current target for cleanup in the mile-long, half mile-wide plume where it is thought that chromium 6 is greater than 50 parts per billion. The balance – about half – is most likely somewhere in between, whether it has washed on or moved out.
“Maybe it got into the Rio Grande years ago and moved beyond, some of it might be in the plume, but I would hazard that a large part of it is in the vadose zone which is above the groundwater but below the surface,” Mikolanis said. “The chromium was released 50 years ago and less than 10 percent of it has made it to the aquifer. The rest of it, if it moves through soils, is going to move very slowly.”
He noted that there are recommendations by EM-LA to characterize what’s upstream of the plume because when the final remedy is in place, which he guesses will be extraction in the plume, the mechanism will be in place to extract and treat any recharging that takes place.
“You’d have to do an awful amount of investigation and studying to find out exactly where it is and you probably wouldn’t find it all. I’m just speculating moving forward, but the game plan right now would be to treat what we have and then keep it operational if the material makes it further into the plume moving forward. As of March this year, we had removed 596lbs of chromium and we’ve removed more than that because now it’s September,” Mikolanis said.
He said one of the key differences of position between NMED and DOE/EM is that DOE believes the interim measure was not designed or intended to be a mass extraction system.
“The interim measure is not a treatment under the Consent Order. Appendix C gave three primary objectives. One was to contain the plume so that it doesn’t get off government land because at the time it was very close to the Pueblo de San Ildefonso lands, but also not to get up here and into the County drinking water supply. The interim measure is there to confine the plume, try to hold it in place while we move to the treatment system which is the final remedy,” Mikolanis said.
He said NMED expects the interim measure, which is pump and treat and re-inject, to remove mass but notes that the system is not designed for that.
“It’s a fundamental disagreement we have and it affects us down to the working levels as well as in some of the management discussions. But I’m engaging with NMED on this. The interim measure needs to stay in place to contain the plume. It was envisioned to be a 4-5 year campaign. When the 2016 Consent Order was signed we moved immediately into putting in place this interim measure, which was a series of five injection and five extraction wells paired up to put a hydraulic barrier in place. It took two years to install the system and it went online in 2018,” Mikolanis said.
He noted that those wells typically cost $6-8 million apiece.
“They’re very expensive and they’re very difficult to place because although Mortandad Canyon is a big wide open space to look at, what you don’t see are all the cultural sites that we preserve there and topographically we’d have to fly in helicopters with drilling equipment to drill in some of the areas. There’s a very limited space to go put these wells in place. Every single one of those wells is precious and it’s very expensive to put drills in there,” Mikolanis said.
While the interim measure has been operating since 2018, when COVID-19 hit in 2020, a lot of work stopped but resumed in 2021. Additional monitoring wells have been placed and more are proposed.
“We are hesitant to put in additional wells until we get this work plan we talked about in place. There’s been a lot of work done to characterize and get the nature and extent of the plume in place. The interim measure was only intended to hold that plume while we did enough studying to get into final remedy,” Mikolanis said. “Going back to 2005 when the plume was discovered, neither the DOE nor NMED’s subject matter experts (SMEs) knew what we needed to do because we didn’t know the nature and the extent.”
He said DOE SMEs now have a model of what they think is happening in the ground but that NMED is “not too fond” of that model yet because at this stage of the investigation the EPA regulatory approach is to see more data and calculations, which are used to refine a model when it’s used to guide regulatory decisions.
“DOE had to build a model in order to formulate how do we attack the problem from the owner of the problem. We have a model that tells us what’s going on under the ground and we’ve calibrated it since the interim measure went in place to five or six years of operational data and modeling data. That’s a pretty powerful tool. It’s not in very many geographic spots but it’s still data rich at the time. We have an understanding of what’s there. If the DOE was left to its own devices, we are ready to head into putting a remedy in place,” he said. “We think we know. We don’t have the depth in a part of the plume nailed down and we were surprised when we put one of our wells in on the eastern edge of the plume and found higher concentrations at a deeper depth where we were expecting to find no contamination or low contamination. There’s an area of the plume that we have to bound for how deep it might be but we know enough about the rest of the plume to start putting a final remedy in place.”
Mikolanis said a final remedy is a misnomer because when DOE proposes a corrective measures evaluation, the final remedy will not be the final remedy.
“As we get more information, as we find things, the remedy is going to change. So the longer we wait to start moving to the larger mass extraction, if we’re not careful, we’ll get into analysis paralysis. There’s always more information we can get, there’s always more studying we can do, always another well we could drill, but when you know enough about the problem the DOE has a bias for action for getting into the final remedy; hence in the FY2022 Appendix B I asked for a work plan that would define what are the minimum data gaps that both agencies feel need to be addressed because every monitoring well we drill should be maximizing the data so that we can move into the final remedy as soon as possible,” he said.
While NMED has publicly stated they have been pushing DOE on LANL cleanup, Mikolanis said his leadership in Washington, DC made it very clear to him when he came to EM-LA that the DOE needs to have a “bias for action”.
“I have a bias for action for putting this final remedy in place and moving to one as soon as possible. It’s going to be a matter of getting the SMEs in the room long enough to say, ‘Here’s what we’d like to have a sense of for the final remedy,’ and then let’s go, because it’s going to take a couple of years.” he said.
Mikolanis believes NMED has a bias for action as well but that they also need to listen to their SMEs who want more data.
“So what I’ve been struggling with and I’ve been working on with my team internally and consulting and discussing with my counterparts with NMED is the need to have supervisors and managers pull the SMEs in together and set some clear expectations and determine what data we have to have. Some of the SMEs have said, we’re not going to get into the final remedy for a couple of years. I think we can do better than that. We have to continue to work with our regulator to hammer down exactly what are the data gaps we need to fill and determine if we can start putting a final remedy in place earlier than that,” he said.
Mikolanis said even if both agencies are ready to go it’s going to take a couple of years to design, procure and install the final remedy system.
“I don’t want to wait for a couple more years of data and then a couple more years of procurement and installation because then I’m not pulling the large mass out for four more years. I’m going to have four more years of NMED saying we’re not pulling out enough mass, well we’ll pull out more mass when we get to the final remedy and I’m confident that working with the leadership in NMED we’re going to get to that point where either we’re moving to the CME faster or I’m going to pilot something,” he said.
He said the bottom line is NMED keeps reiterating that DOE is not meeting NMED’s expectations because DOE is not extracting chromium at a fast enough rate.
“The interim measure does not treat the plume; the remedy will treat the plume,” Mikolanis said