With groundwater cleanup at the Energy Department’s Idaho Site progressing slower than expected, DOE is giving itself until September 2019 to test out some fixes, an agency official told members of an agency-chartered citizen group last week.
That is according to slides Nicole Badrov, a senior DOE manager in Idaho, presented to the Idaho National Laboratory Site Environmental Management Citizens Advisory Board on Feb. 17. Badrov’s slides, posted online days after the meeting, detailed the results of the latest five-year review DOE formally completed earlier this month in accordance with Environmental Protection Agency rules about Superfund cleanup sites. The review, which required approval from EPA and the state of Idaho, assessed cleanup progress at the Idaho Site from 2010 to 2014.
The contaminated groundwater at issue stretches about 1,000 feet east to west beneath Test Area North, which from 1953 to 1972 pumped both nuclear and non-nuclear liquid waste into the groundwater at DOE’s Idaho National Laboratory as part of a never-completed effort to develop technology for a nuclear-powered aircraft.
EPA officially considers this groundwater contamination “under control,” meaning it is not expected to escape to the surface.
The latest five-year review found concentrations of trichloroethylene, a potentially cancer-causing metal degreaser, have not decreased as expected. The report recommended DOE continue “in-situ bioremediation rebound” tests, which attempt to break down organic contaminants where they lie by pumping food substances such as whey and lactose into contaminated soil.
DOE has long said that in-situ bioremediation, one of several groundwater treatment methods used at the Idaho Site, would become less and less effective as treatment continued and fewer ground contaminants remained to be broken down. However, with trichloroethylene concentrations not decreasing as expected, the viability of the food-based treatment is in question. DOE therefore decided to try in-situ bioremediation on a pocket of contamination that hasn’t been treated yet to investigate whether the problems observed so far are related to the technique itself, or to the site where it was already applied.
Meanwhile, groundwater concentrations of the radioactive isotope cesium-137, a byproduct of uranium fission, are increasing rather than decreasing near Test Area North, the review found. Likewise, concentrations of another uranium fission byproduct, strontium-90, have not decreased as expected. According to the review, once DOE completes its in-situ bioremediation regimen, the department will again measure the level of radioactive groundwater contaminants and decide from there how to clean them up.
Finally, the review found, DOE might not be able to track the expanding plume of groundwater contaminants as well as federal law requires. The department’s fix includes installing another well at the site so the agency has another standpoint from which to monitor the plume.
