"Our most material source of waste is lubricating oil and ensuring its responsible disposal is our main focus. We use 2.1 million litres of it every year. Lubricating oil is required to ensure the performance and efficiency of our landfill gas engines. After use, we sell our lubricating oil on to a specialist organisation for processing. Over a number of years we have worked closely with oil suppliers to develop optimum oil blends for the harsh operating conditions within landfill gas engines due to landfill gas contaminants. As a result, our oil use efficiency has dramatically improved, along with its related environmental impact."