2008-07-22 Resolution_702-08_re_Violations_of_federal_clean_air_act_gas_emissions_and_controls_for_West_Hawaii_Landfill

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2.2 REMEDIAL STRATEGIES Subsurface landfill fires are difficult to extinguish,potentially requiring an extended period of time and significant labor and financial resources. Historically,fire suppression methods consisted of inundation or suffocation,where one of the three requirements for combustion(fuel,02, and ignition)was eliminated. Given that the landfill is composed of a high percentage of combustible waste products,the fuel supply cannot be readily eliminated except through separation or completion of the combustion cycle. Such an approach may include the continued,although controlled combustion of the waste in the landfill with the implementation of external emissions capture systems to prevent downstream impacts. Suffocation eliminates the 02 supply by interrupting the source or by the introduction of agents that replace the 02 in the surrounding environment, thereby starving the 02 pathway. Suffocation may alternatively involve excavation,segregation,and smothering the smoldering waste with soil or fire-retardant materials. Inundation extinguishes fire by eliminating the ignition source (the ongoing fire),may be accomplished by applying fire suppressants such as water,foams(such as Class A foam [CIWMB,2007])and other chemicals. The success of the inundation technique was proven during a subsurface fire suppression demonstration at an undeveloped landfill area within the Candlestick Point State Recreation Area in San Francisco,California. The suppression technique involved trenching to expose the on-going fire and spraying it with a fire retardant foam to extinguish the fire. A similar technique is proposed for demonstration at the Kailua-Kona Landfill. 2.3 SITE INVESTIGATION APPROACHES 2.3.1 General Approaches To gain a better understanding of the nature and extent of the subsurface fires that currently exist at the landfill,and to predict the future potential of subsurface fires,a physical and chemical investigation will be conducted. According to the California Integrated Waste Management Board (CIWMB) (2007)and the Federal Emergency Management Agency (FEMA) (TriData,2002),a subsurface fire can be confirmed by: • Substantial settlement over a short period of time; ERM 7 KAILUA-KONA LANDFILL/0061204-3/14/2008