TherraTherm cleans up big mess with innovative approach

  • Published
  • By Philip Lorenz III
  • AEDC/PA
Arnold Air Force Base, Tenn. --  A large-scale soil and groundwater remediation effort is underway at Arnold Engineering Development Center (AEDC) using innovative technologies.
 
"This [improved thermal remediation technology] is like a big sledge hammer," said Greg Sandlin, ATA's [Aerospace Testing Alliance] installation restoration engineer. "It will take care of business."

Denny Timmons, AEDC's Restoration Program Manager, said the contaminant being removed from the area behind the Model Shop is perchloroethlyene, also known as PCE.

"It's one of the bigger remediation projects in the country," he said. "We are doing thermal remediation to remove 99 percent of the PCE at this site. This is the largest thermal remediation effort that the contractor [TerraTherm] has conducted to date, in terms of acreage and depth.

"What we call 'pump and treat' methods work, but they take years and the risk of contaminates mobilizing and migrating off base pose too great of a risk," Timmons added.

Sandlin put the methods being used on the large project into perspective.

"Thermal remediation and steam heating have been in existence for several years, but significant technological improvements only recently made these methods a practical option for use on base," he said.

Dennis Flatt, ATA's program manager for the restoration program, said a lot of pre-planning went into the remediation project which will take approximately seven months to complete.

"We've done a tremendous amount of forward thinking to avoid mission impact because the facilities all around this site are continuously used," he said. "Safety is a top priority and the remediation site is in a fairly busy area adjacent to our model shop which is mission critical. We've had to work with logistics, traffic control and materials storage to allow multiple drill rigs to remain on schedule. ATA has replaced waterlines, electric power and assisted with necessary permits to accommodate the contractor requirements. By comparison, this site is much more complex than many of the other thermal sites that have been done to date because of the total volume of the mass that they're dealing with and the depth at which it is located."

The extracted groundwater will undergo treatment by air stripping and activated carbon, while the PCE-laden vapor will be destroyed in a thermal oxidizer with the exhaust gases treated by an acid gas scrubber.

For more details, contact Denny Timmons at (931) 454-4353.