ROY — Hill Air Force Base environmental officials believe they have stopped the spread of trichloroethene contamination in a milelong plume under the southern part of the city.
Containment of the spreading TCE, a probable carcinogen, is part of phase one of a cleanup process that is expected to take up to 30 years.
Environmental engineer Mark Loucks said more than 100 test wells have been dug to determine the spread of the degreasing agent used at the base in the 1960s and 1970s.
The Air Force has installed a cleanup well on the eastern border of the city that has removed 1.7 million gallons of groundwater and the test wells indicate it has effectively stopped the flow of contaminants, Loucks said.
The contaminated water is treated and then released into the North Davis County sewer system.
As part of phase two of the cleanup, the Air Force plans a system on the western side of the plume area that will run contaminated water through a mixture of iron and sand to break down the contamination. The property where that system would be located is owned by the Utah Transit Authority, and discussion about access to the site is continuing, Loucks said.
Another part of phase two is to determine the extent of any possible contaminants and their fumes in the groundwater of homes. So far, 130 homes have been sampled. Detectable contaminants have been found in 13 homes.
The Air Force has installed vapor removal systems to eliminate fumes in those homes. Loucks plans to renew sampling of homes in November.