An analysis of the variables which affect the recovery of landfill gas was carried out. In order to understand the working of biogas wells, a non-sophisticated mathematical model was proposed. Then, a method for controlling the rate of landfill gas extraction was defined using the composition of the extracted gas as the control parameter The end result of the practical application of this method in the sanitary landfill of the La Zoreda (Asturias, Spain) showed that the control parameter could be successfully employed on an intermittent basis using manual controls and that it did not require extensive automation.