Abstract: A method for treating oxidable gas generated from waste at a dumping area and to the structure of the dumping area. The dumping area has an organic waste layer covered with a sealing layer that prevents the absorption of water, with a drying layer and a surface layer. Oxidable gas is generated and directed through an aperture formed in the sealing layer and made to spread in, the lateral direction with the help of one or several flow controllers so that the gas ends in the surface layer to become biologically oxidized. The aperture may be provided with a cover, and the gas flow controllers may be perforated pipes extending radially from a side of a well. The oxidation of gas may be intensified by directing air and/or moisture from a piping to the surface layer.