BY MAIRE O’NEILL
The New Mexico Environment Department does not feel that the pace of Los Alamos National Laboratory legacy waste cleanup is quick enough, Acting Director of Resource Protection Chris Catechis told a recent meeting of the Legislative Radioactive and Hazardous waste committee
Catechis said because of this, in February NMED entered into a civil complaint with Department of Energy regarding the speed of cleanup.
“Our ultimate goal is to negotiate and get a new Consent Order which would replace the one from 2016. Hopefully that’s going to give is a little more ability to direct the pace of the cleanup with DOE and hold them a little more accountable and ultimately get that legacy cleaned up and get it off the hill which is the ultimate goal for both NMED and DOE,” Catechis said.
He said the hexavalent chromium project is a good example of where NMED needs to have a firm Consent Order that really allows the state to have more teeth in holding DOE accountable. He said the project involved approximately 160,000 pounds of hexavalent chromium that was released from 1956 to 1972. The chromium plume was discovered in 2005. Since that time, Catechis said, NMED has been working with DOE to really get a fee for the size of the plume and its borders.
“Then we can go in and put in some remedial actions to get this thing ultimately cleaned up. From NMED and DOE, we don’t want to make this problem worse. We don’t want to affect groundwater and create additional contamination in the area and so we want to make sure that this project’s done right,” Catechis said.
He noted that “2005 has been quite a while”. He said NMED thinks it will be a few years before there is a really firm answer on just the size of the project.
“We’re still looking at getting some more monitoring wells put in place to make sure we have a firm grasp on it. DOE has put in some interim measures for cleanup that NMED doesn’t feel have been that successful. Of the original 160,000 pounds, only 470 pounds have been removed. In my position, it really has not been an effective interim measure so we’d like to see more resources put into this from the DOE side to get this ultimately cleaned up,” Catechis said.
Later in the meeting, DOE Environmental Management Los Alamo Field Office Manager Mike Milolanis offered his perspective on how the chromium interim measure is working.
“When the interim measure was initially installed, the most urgent task was to stop the migration of the southern portion of the plume towards the property boundary that we share with the San Ildefonso Pueblo. That’s where the hexavalent chromium plume was located when the interim measure was started close to the boundary and the primary objective of the interim measure was to create a hydraulic barrier that could reverse the groundwater flow and push the plume back and further away from the pueblo boundary,” Mikolanis said.
He noted that prior to putting the interim system into operation, the concentrations of chromium in the groundwater were at Well 50 right by the boundary of San Ildefonso Pueblo.
“That’s the closest monitoring well to the property. The concentrations in the groundwater there were steadily increasing and were approximately three times the groundwater standard of 50 parts per billion for New Mexico. Today, with the combination of extraction, treatment and injection, we’ve controlled the downgrade migration, we’ve pushed the flow back 500 feet from the pueblo’s boundary and the concentration at Well 50 is showing approximately 92 percent reduction in the chromium as compared to when we started. That’s a significant improvement,” Mikolanis said.
He explained that chromium is extracted and processed and then the purified clean water is re-injected.
“As we’re drawing and pushing back the plume, we’re cleaning it as Dep. Sec. Roose pointed out, we’ve pulled out about 450 pounds or so in the time that we’ve been extracting material. In FY20 and FY21, we extracted and processed and injected 180 million gallons of water from the plume that resulted in about 320 pounds of chromium that was extracted as part of the hydraulic barrier. But the interim measure is only a temporary thing and our focus moving forward is to get the information necessary to characterize the plume to the point where we understand what the final remediation ought to be,” Mikolanis said.
Mikolanis listed some accomplishments on the chromium project including the retreat of the plume boundary 500 feet or so, the installation of two new groundwater wells, R-71 and R-72.
“We have drilled them to 1700 feet below grade and are building the internal casing for the well itself. Looking forward, we’re putting in R-73 to the east – DOE and NMED interested in characterizing the ‘finger’ on the map. We have seen decreasing concentration in that are but need a little more time before we can pop any champagne corks on whether it’s as effective as it was on the southern boundary,” he said.
Mikolanis noted that NMED has also proposed some additional locations that DOE-EM is currently evaluating.
“But the Department of Energy’s bias is for action. We are collaborating as best we can with the regulator. I partner with my contractors and I collaborate with my regulators, to develop a strategy that helps us transition from one of groundwater monitoring to one that is design, whether it’s a pump and treat extraction or some other final remediation that lets us address the plume in the near term,” he said.