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Tak Airport North Apron Decontamination > 1,800
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Tak Airport North Apron Decontamination
Biopiles for the treatment of contaminated soil.
Air Sparging and Soil Vapour Extraction in-situ treatment
for contaminated soil.
Kai Tak Airport before decommissioning.
new Hong Kong International Airport commissioned at Chek Lap
Kok in July 1998, the disused Kai Tak Airport, an area of
about 160 hectares, would be redeveloped as housing flats,
offices, parks and community facilities for about 115,000
residents. Three hotspots in the Kai Tak Airport North Apron,
totaling about 11 hectares, were found to be contaminated
by jet fuel leakage and had to be cleaned up before redevelopment.
The scale of this decontamination work was the largest of
its kind ever undertaken in Hong Kong.
Permit was issued on 23 September 1998 for this project, which
was started on 26 October 1998. Key activities included decontamination
of the airport site, demolition of buildings and site preparation.
The project would be completed in 2001.
Mitigation Measures and Outcomes
Soil Vapour Extraction and Air Sparging (SVE/AS) method
was adopted to treat contaminated soil in-situ to avoid
large-scale excavation and the associated escape of vaporized
contaminants into the atmosphere.
Heavily contaminated soil was excavated and treated in "biopiles",
which were piles of soil lined with impervious plastic sheets
on top and bottom to allow biodegradation of the contaminants
while avoiding the escape of vaporized pollutants as well
as containing any leachate runoff.
The SVE/AS and biopile systems were connected to a catalytic
incinerator by piping network to burn off any pollutants
in the extracted soil vapour.
Proper soil decontamination using these two methods protected
about 700,000 people, including workers and nearby residents,
from any excessive air pollutants and noise impacts associated
with other cleanup methods that employ large-scale excavation.
Good housekeeping measures were adopted on site to include:
excavation work to avoid the rainy season in order to
reduce the potential of generating contaminated surface
quieter plants to reduce construction noise impact.
to suppress dust during the demolition stage.
all waste, including chemical wastes and oil, by licensed
chemical waste contractors.