EXTINGUISHING THE DELTA SHAKE AND SHINGLE LANDFILL FIRE 

Strategy for Extinguishment.
Three ingredients are necessary to initiate and sustain a landfill fire: 1) a fuel supply, 2) oxygen and 3) a high temperature ignition source. These three components define the "Fire Triangle". Extinguishment of a landfill fire can be realized by removing any one of the fire triangle components.

In determining the most effective method of fire extinguishment at the Delta Shake and Shingle site, the following six methods were considered.

• Accelerated high temperature combustion;
• Capping of the landfill burn area with soil;
• Capping of the burn area with geomembrane;
• Flooding the burn area with water from the Fraser River;
• Injecting an inert gas such as CO(2) to displace oxygen; and
• Excavating the burning material and then extinguishing it with foam.

The idea of accelerating the burn was abandoned due to air quality concerns and the risk of spreading fire into the main fill zone. Capping of the landfill with soil was discounted due to the risk of initiating further slope failures on the steep side slopes. Application of a geomembrane cap was not considered practical on the steep slopes approaching 1.sH:1V. Also, there were concerns that the membrane would melt before the fire was extinguished. Flooding the burn area with large volumes of water was not pursued due to geotechnical stability concerns and potential leachate impacts. Oxygen displacement using CO(2) was not considered practical due to the porous nature of the waste and the lack of cover soils that would prevent the injected gas from escaping.

The only practical method of extinguishment was to excavate the burning material and then transport it to a lay down area where it could be soaked with water and extinguished.    

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