NOVELTY - Biodegrading municipal solid waste, comprises placing a first lift of waste material on top of leachate withdrawal piping which is on a bottom of landfill bioreactor, placing a first piping layer on first lift top, placing a second lift on top of first piping layer, placing a second piping layer on second lift top and introducing air into second lift using first piping layer.    USE - The method is useful for biodegrading municipal solid waste.    ADVANTAGE - The method increases landfill density and capacity, accelerates landfill aerobic and/or anaerobic degradation, and improves degradation by-product quality.    DETAILED DESCRIPTION - Biodegrading municipal solid waste comprises creating a landfill bioreactor having a bottom surface (14), locating leachate withdrawal piping (12) on the landfill bottom surface, placing a first lift (20) of waste material on top of the leachate withdrawal piping to form a first lift; placing a first piping layer on the first lift top surface (22), placing a second lift (28) of waste material on top of the first piping layer to form a second lift, placing a second piping layer on second lift top surface (30) and introducing air into the second lift using the first piping layer.    An INDEPENDENT CLAIM is also included for a landfill bioreactor comprising a bottom including leachate piping associated with a leachate withdraw pump (56), a berm, a first lift of waste material including compostable waste, a first piping layer on the first lift top surface, a second lift of waste material, a second piping layer located on second lift top surface, a third lift (34) of waste material and a third piping layer (50) on the third lift top surface (36).    DESCRIPTION OF DRAWING(S) - The figure shows a side cross-section view of the landfill bioreactor.    Leachate withdrawal piping (12)    Bottom surface (14)    First lift (20)    First lift top surface (22)    Second lift (28)    Second lift top surface (30)    Third lift (34)    Third lift top surface (36)    Third piping layer (50)    Leachate withdraw pump (56)