Anaerobic digestion is a microbial process that converts organic carbon to “biogas”, a gas composed primarily of methane and carbon dioxide. A growing number of larger dairies are anaerobically digesting manure to reduce odors and pathogens, and produce biogas for heating and electricity. In 1997, a research group at Cornell University completed a study for the USDA - Natural Resources Conservation Service to evaluate the feasibility of community digesters in New York State. This fact sheet was developed from the results of their final report, Evaluation of Anaerobic Digestion Options for Groups of Dairy Farms in Upstate New York.