Cleanup contractor Fluor Idaho is moving forward with a plan to test 11 groundwater wells on the U.S. Department of Energy’s desert site after a hazardous chemical showed up in preliminary tests of two of the wells last year.
Early last month, the U.S. Environmental Protection Agency and the Idaho Department of Environmental Quality approved a plan to take water samples and shoot video inside 11 wells that officials suspect could contain tetrachloroethylene, or PCE. A clear chemical liquid, PCE often is used for dry cleaning and as a metal degreaser.
Officials don’t think the East Snake Plain Aquifer itself is contaminated with PCE. They believe the contamination is isolated inside sealed shafts of a certain brand of well called Westbay. But the fact that they don’t know how the chemical got inside at least two of the wells makes officials uneasy, and has spurred them to continue testing and solve the mystery.
The approved field sampling plan will get underway once the snow melts this spring. Fluor officials plan to collect several samples from each well that will be sent to a lab for testing, said Jeff Forbes, a Fluor hydrogeologist.
They also will send a special camera down the well shafts to see if they can find where the PCE is coming from. Video taken from the two wells that already tested positive showed some strange, dark material floating in the water, Forbes said.
While they wait for the weather to improve, Forbes and others have been using some detective skills to try and figure out the history of the wells over the last decade — who filled the wells with water, who took samples from each well, and when, and if the sampling equipment may have inadvertently contaminated the water.
The 11 Westbay wells, nearly a quarter-mile deep, were filled with an outside water source when they were installed about a decade ago, and that water has remained separate from the surrounding aquifer.
There are dozens of similar monitoring wells positioned around the DOE site, ensuring nuclear cleanup and research activities aren’t polluting the aquifer.
A cleanup plan for the contaminated wells will be developed following the testing.
Luke Ramseth can be reached at 542-6763. Twitter: @lramseth