(VNF) - Vietnam and the United States marked the start of the second and final phase of thermal treatments at Da Nang on October 18^th, to clean up dioxin contamination stored during the war between the countries.

Dioxin contaminated soil pile at the Da Nang Airport. (Photo: VNN)

This phase targets approximately 45,000 cubic metres of soil and sediment contaminated by dioxin (the defoliant also known as Agent Orange). The project is of great benefit to the people of Da Nang and is of historic importance for the bilateral relationship.

Attending the event, Senior Lieutenant General Nguyen Chi Vinh said the ongoing project reflected a strong commitment of the two governments.

“We witnessed the first successful phase of the project, and the Government of Vietnam urged relevant agencies to speed up the second phase and return a safe and clean space for Da Nang City to build a second terminal at the airport in preparation for the 2017 APEC (Asia-Pacific Economic Co-operation) Summit,” Vinh said.

“I would say to the US President at the APEC Summit that the site, which used to be a former airbase and battle site, has been wiped free of dioxin contamination in a joint effort between Vietnam and the US,” he added.

"In a moment we will ceremonially start thermal treatment for the final batch of contaminated soil and sediment. I am encouraged by how this project continues to be a symbol of our honesty about the past, dealing with what remains and turning an issue of contention into one of collaboration," US ambassador Ted Osius said at the scene, according to a statement.

The first phase of the clean-up, which also treated 45,000 cubic metres, was completed in May.

"The long-term impact of the project will be the elimination of potential health risks associated with dioxin exposure from the site," the US embassy statement said.

Ambassador Osius (R) and Vietnam's Deputy Minister of National Defense Nguyen Chi Vinh at a ceremony in Da Nang, where they were photographed before a giant mound of covered earth. (Photo: AFP)

The thermal technology heats the contaminated soil to temperatures high enough to break down dioxin into harmless compounds.

Da Nang Airbase was a key site in the defoliant programme, and much of the 80 million litres (21 million gallons) of Agent Orange used during "Operation Ranch Hand" was mixed, stored and loaded onto planes there.

The airbase is considered a "dioxin hotspot", where concentrations of toxic contaminants from Agent Orange are well above the globally-accepted maximum standard. The government says up to three million Vietnamese were exposed to Agent Orange, and at least 150,000 children were born with birth defects as a result.

In all, the Environmental Remediation of Dioxin Contamination at Da Nang Airport will treat an estimated 90,000 cubic metres of contaminated soil and sediments to a level below the Government of Vietnam standard of 150 parts per trillion.

As scheduled, the contaminated soil and sediment will be heated by 1,254 heating wells to a temperature of 335 degrees Celsius over four months, with approximately 95 per cent of the dioxin estimated to be destroyed within the structure.

The five-year project draws on a total fund of USD 84 million, of which VND 35 billion (USD 1.6 million) comes from the Vietnamese Government./.

( Compiled by VNF )