To evaluate the effects of earthworm cast and PAC amendments on the CH4 removal capacity of the landfill cover layers, three different materials-typical landfill cover soil, mixture of landfill cover soil and earthworm cast (6:4, w/w), and mixture of landfill cover soil and PAC (6:4, w/w), were prepared. The earthworm cast and PAC were purchased commercially (Forgreen Co., and Jeil Carbon Tec, Korea). Moisture content, organic matter content, and pH of earthworm cast used in this study were 20.1% (w/w), 33.7% and 7.32, respectively. Moisture content and pH of PAC were 25.2% (w/w) and 9.0,
respectively