Landfill gas consists mainly of methane and carbon dioxide. Methane is combustible, easily flammable and, after carbon dioxide, the most important greenhouse gas. Its greenhouse effect is 20 to 30 times more potent than that of carbon dioxide. If no action is taken, the gas will escape, spread noxious odours, and contribute to the greenhouse effect. Because of its detrimental effect on the climate and for safety reasons methane has to be disposed of safely, i.e. burnt off or used for energy generation. We build and operate gas utilisation plants comprising gas wells, a control station, and an extraction station. Landfill gas is first dried, then purified, and finally converted into electric power by gas engines. The gas engines are fitted with an exhaust gas reactor to reduce the emission of air pollutants. The condensate produced in the course of landfill gas purification is drained into the leachate water purification system.