EXTINGUISHING THE DELTA SHAKE AND SHINGLE LANDFILL FIRE
Extinguishing
the Fire.
The first step in controlling the fire was to fill in the
trenches previously excavated by the landfill owner. This action
reduced the amount of air fanning the burn and made the landfill
surface a safer work environment. Next, the fire zone was smothered
with a 2 to 3 m thick lift of refuse. Over a two day period two
D6 bulldozers were used to cover the fire zone with unburned waste,
thus limiting the availability of oxygen and slowing down the
rate of burn. As shown in Photo5
and Photo6, this
action dramatically
reduced the rate of burn and the amount of smoke that the fire
was emitting.
Initially,
water was applied to the fire in high pressure streams from several
high capacity monitors with a combined output in excess of 1,300
L/s. Although successful in extinguishing flames at surface, application
of water was not effective in extinguishing the fire at depth.
Instead, most of the water quickly ran off the surface to the
landfill toe where pools of toxic black leachate were formed.
The effectiveness of the monitors was increased by deploying the
water at a reduced rate as a mist over the fire area. Also, to
improve the penetrating properties of the water, Class-A foam
was added at an application rate of 0.05%.
Once
the fire was brought under control, two large excavators and six
CAT D350D articulated off-road trucks were mobilized to excavate
and transport the burning waste from the horseshoe to the cool
down areas. Because ignition of the main fill zone represented
everyone's worst nightmare, the excavators were directed to work
around the perimeter of the horseshoe until a reliable fireguard
was established down to inert soil and concrete rubble. The remainder
of the 250,000m(3) were then worked over.
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Continue
with extinguishing the fire
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