Impact of Landfill Closure Designs on Long-Term Natural Attenuation of Chlorinated Hydrocarbons

摘要

The subject of this cost and performance report is a pilot-scale field demonstration of a recirculation bioreactor at Landfill 3 (LF-03), Altus Air Force Base (AFB), Oklahoma. The purpose of constructing and operating the bioreactor was to demonstrate that a combination of organic material addition and accelerated leaching can rapidly reduce source area concentrations of chlorinated aliphatic hydrocarbons (CAH) in groundwater at unlined, closed landfills. Hundreds of landfills on Department of Defense (DoD) installations have generated CAH plumes in groundwater. Surface covers, which are intended to provide a barrier to prevent direct contact with waste material and minimize or eliminate infiltration of precipitation through the waste material (i.e., leachate formation), are the current method of choice to manage human and ecological risks at these sites (Bagchi, 1990). In some cases, impermeable covers may impede natural attenuation processes by reducing the quantity of organic-rich leachate that promotes the bioremediation of CAHs. The results of this project will provide environmental engineers with an additional perspective on treatment of dissolved volatile organic compound (VOC) plumes originating at unlined landfills (and at non-landfill source areas).