Detection of Aluminum Waste Reactions and Waste Fires

Aluminum production wastes (APW) placed in Subtitle D regulated landfills may react exothermically and cause uncontrolled temperature increases, large volumes of explosive and toxic gasses, increases in landfill gas pressure and flow, intense odors, undesirable changes in leachate composition, increased leachate production, and most importantly, smoldering combustion of the surrounding solid waste. The landfill liner and explosive gas extraction and leachate collection systems can be damaged by heat from the reaction and/or accompanying combustion. Slope failure also may result from increased gas and liquid pressures and the reduction of waste mass shear strength attributable to subsurface combustion compounding existing or initiating damage to engineered components. Therefore, landfills that have received APW need early detection of a potential exothermic reaction to respond promptly to prevent subsequent subsurface combustion. This paper presents techniques to quickly evaluate landfill gas and temperature data to determine if an APW reaction is occurring, discusses operational indicator criteria that can be used to differentiate an APW reaction from subsurface combustion or combined reaction/combustion, and provides recommendations for APW disposal that minimize potential for a reaction to occur. (C) 2013 American Society of Civil Engineers.