The U.S. EPA’s AgSTAR program has been tracking data on farm-based livestock manure anaerobic digestion (AD) for 20 years. A September 2020 update of farm-based manure digesters shows a trend toward renewable natural gas production. Its most recent update found 263 operational projects in the U.S., and 17 in construction (see chart, above). Digesters processing dairy manure lead the pack with 211, followed by digesters that process swine (45), poultry (8), and beef (8) manures. This total exceeds 263 because some projects accept manure from more than one animal type. More>>