The decontamination programme will be conducted over three phases: site characterization, interim containment and long-term cleanup.
The first two phases have been completed in the northern part of Da Nang airport. Between 2005-2007 more than 300 samples of soil and sediments were taken for testing to see whether or not they contained dioxin and related persistent organic pollutants.
At spots that were used to store, mix and load the dioxin onto aircraft, the level of dioxin surpasses the 1 part per billion (ppb) toxic equivalence per kilogram – the level required for the clean up.
Samples of blood and breast milk were also taken from people living and working on and around the northern end of Da Nang airbase, and in the surrounding community. The tests showed that the levels of TCDD (the most toxic dioxin, and specific to Agent Orange) in the majority of the tested people far exceeded 3-7 parts per trillion (ppt) range by a wide margin.
Dioxin concentrations in the blood of 9 of the 11 workers at Sen Lake A and in 9 of the 11 workers at the lakes just to the west of the airbase exceeded 10 ppt. The actual levels ranged from 19.7 to 1,150.0 ppt for Sen Lake A workers and from 14.0 to 77.7 ppt for the workers west of the airbase.
Seven of the 16 residents of Thanh Khe District just north of the airbase also exceeded the 10 ppt level, ranging from 12.5 to 68.1 ppt.
The Center for Environmental Treatment Technology under the Ministry of Defense has designed and brought into action five interventions to stop the further accumulation of dioxin-contaminated soil and sediment in Sen Lake A, halt food production from the lake and prevent public access to the lake and surrounding area.
Vietnam aims to have the areas free of toxic waste by the end of 2008. The project has been implemented by the Ministry of Defence with technical support from the US Environment Protection Agency (USEPA), Hatfield Consultants of Canada and BEM Systems from the USA. The funding for phases 1 and 2 was provided by the Office of Committee 33 (US$19,945), the US State Department and USEPA (US$410,000) and the Ford Foundation (US$769,300).
According to statistics, more than 20 million gallons of Agent Orange and other herbicides were sprayed by US forces on southern and central Vietnam between 1961 and 1971.
