Environmental remediation of dioxin contamination at Da Nang International Airport
On the morning of August 9, 2012, the Ministry of National Defense and the United States Agency for International Development (USAID) held a groundbreaking ceremony for the dioxin remediation project at Da Nang airport.
Previously, the agreement on implementing the Project “Environmental Treatment of Dioxin Contamination at Da Nang Airport” was signed between the Vietnamese Ministry of National Defense and USAID in May 2011. The project aims to clean up dioxin-contaminated soil and mud below the Vietnamese Government’s cleaning standards, prevent the spread of pollutants into the air and water, and protect the health of people, surrounding communities, and staff working at the airport. Accordingly, the project will use 41 million USD in non-refundable ODA capital from the US Government (managed and implemented by USAID) and 35 billion VND in counterpart capital from the Vietnamese Government (managed and implemented by the Air Defense - Air Force Service under the Ministry of National Defense).
Bomb and mine clearance to handle dioxin at Da Nang airport photo: Internet
Accordingly, approximately 72,900 cubic meters of dioxin-contaminated soil and sediment over a total area of more than 191,400 square meters at Da Nang Airport (including Sen Lake and wetlands, mixing and transfer areas, former storage areas, drainage ditches and central areas) will be excavated, placed in a containment structure at the construction site and subjected to high-temperature thermal desorption (3350C) to decompose the dioxin. The treated soil and sediment will be removed from the containment structure and tested to ensure that there is no contamination and will then be used as in-situ landfill material at Da Nang Airport.
With the concentration of dioxin contamination determined at Da Nang Airport being very high. Of which, the highest concentration concentrated in the area where chemicals were mixed and loaded onto aircraft was reported to be up to 17,500 ppt, 17 times higher than the US standard (1,000 ppt). The Vietnamese Ministry of National Defense and USAID have agreed on in-pile thermal desorption technology (IPTD, also known as thermal treatment) to be applied to environmental treatment at Da Nang Airport.
“Safety measures will be implemented to ensure the surrounding environment,” said CDM Smith, the project’s construction management and supervision contractor. “These measures will include the control of dust, surface runoff and steam/moisture emissions. The soil will be kept moist to minimize dust, the project will be shut down during high winds, and air quality will be monitored by monitoring stations. Water that comes into contact with contaminated soil will be collected, monitored, tested and treated before being released into the environment. Workers on site will be monitored and required to wear appropriate personal protective equipment. Any contaminated vehicles will be decontaminated before entering clean areas.”
Starting from September to December 2012, the IPTD contractor will mobilize and import machinery and equipment for activities in 2013. The project is expected to be completed by the end of 2016. Previously, the Ministry of National Defense conducted bomb and mine clearance at the Da Nang airport construction site.
Once completed, the project will create 29 hectares of clean land for economic and commercial purposes, eliminating the potential risk of dioxin contamination for people around the Da Nang airport area, and marking the development of a good international cooperative relationship between the Government and people of Vietnam and the United States.
According to the Vietnamese Ministry of National Defense, Da Nang Airport, along with Bien Hoa (Dong Nai) and Phu Cat (Binh Dinh) Airports, are considered by the Vietnamese government as dioxin “hot spots” due to high levels of dioxin residue in soil and mud over many decades.
According to (giaothongvantai.com.vn)-LT