EPA is promulgating today a site-specific rule proposed on April 16, 2001, to implement a project under the Project XL program. The rule provides site-specific regulatory flexibility under the Resource Conservation and Recovery Act (RCRA), for the Buncombe County Solid Waste Management Facility, Alexander, Buncombe County, North Carolina ("Buncombe County"). The terms of the XL project are defined in a Final Project Agreement (FPA) signed by Buncombe County, the State of North Carolina, and EPA on September 18, 2000. Today's rule is applicable only to the Buncombe County Solid Waste Management Facility, to facilitate implementation of the XL project to use certain bioreactor techniques at its municipal solid waste landfill (MSWLF), specifically, the recirculation of landfill leachate, with the possible addition of water, to accelerate the biodegradation of landfill waste, to decrease the time it takes for the waste to reach stabilization in the landfill, and to promote recovery of landfill gas. The principal objective of this XL Project is to demonstrate that leachate can safely be recirculated over a liner that differs from the liner prescribed in EPA MSWLF regulations. Under existing regulations, leachate recirculation in Cells 1 and 2 is authorized because those cells were constructed using the prescribed composite liner. Today's rule will allow leachate recirculation over an alternative liner for Buncombe County landfill Cells 3 through 10. It is conditioned on Buncombe County's implementation of the design in today's rule. The landfill liner design for Buncombe County will be enforceable in the same way that current RCRA standards for a landfill are enforceable to ensure that management of nonhazardous solid waste is performed in a manner protective of human health and the environment. Today's rule will not in any way affect the provisions or applicability of any existing or future regulations. EPA retains its full range of enforcement options under this rule.