By Anna Liisa Covell
July 29, 2013
Hanoi, Vietnam – The Embassy of the United States of America talks about dioxin clean-up at Da Nang International Airport.
Chief of Environment, Science, Technology and Health, Eric M. Frater said USAid, in conjunction with Vietnamese government, agreed to clean-up environmental contamination at Da Nang International Airport caused by dioxin – dioxin, a by-product of Agent Orange residue left from spraying campaigns of Vietnam War.
Frater said, “73,000 cubic meters of earth will be treated in a remediation process which is slated to be complete in 2016.”
The project consists of building super ovens to bake contaminated soil to destroy dioxin. The process is called “thermal desorption treatment” to rid the environment of toxins. Experts said Agent Orange is dissipated by sunlight and rain. But the long term effects of dioxin remain in the soil which has a scientific shelf-life of over 500 years.
“Hatfield Consultation Environmental Research provided limited analysis for the clean-up at Da Nang International Airport,” Frater said.
The first step in the process is for USAid to build a super oven at the end of Da Nang’s International Airport’s tarmac. The oven will be located in the vicinity of where United States military personnel stored Agent Orange shipments during 1961-1972.
In the remediation process, dioxin-contaminated soil will be heated to over 800 degree Celsius by heating rods that are installed in the oven. The oven will have electric heater system that consists of heater wells or evenly spaced heating rods. Each rod has a minimum target heating potential of 335 degrees Celsius.
Safety precautions at the clean-up site will be in compliance with United States regulations concerning environmental hazard sites to protect workers from dioxin exposure.
“A committee of experts from USAid, Vietnam and United Nations will verify that at least 95 percent of dioxin has been removed from the soil at the end of the process,” Frater said. “Any liquid or vapors will be put though a secondary extraction method to clean the dirt.”