Anaerobic Waste Facility, Uganda (IMAGE) Terry Collins Assoc Caption Biogas, approximately 60 percent methane by volume, is generated through the bacterial breakdown of organic matter in an oxygen free system. Credit Corinne Schuster-Wallace, UNU-INWEH Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.