By Mahmoud Sharara, North Carolina State University

Digesters are becoming increasingly common on animal farms across the country[1]. North Carolina is leading the nation in most digesters built on swine farms (10 systems) with more set to come online in the coming year.

This technology helps the farm on multiple fronts. First, digesters capture methane (a greenhouse gas) that is produced from the breakdown of manure and make it available as a fuel. This creates revenue opportunities to the farm from two sources. (i. the sale of fuel, and ii. economic credit for avoided release of methane to the atmosphere). Digesters also reduce organic solids entering the lagoon and, as a result, limit the accumulation of sludge and greatly reduce the lagoon odor potential.

Recognizing the benefits of this technology, the North Carolina General Assembly instructed the NC Division of Water Resources to develop a general permit for the establishment and operation of digesters. This permit is currently undergoing renewal and will be finalized to take effect in 2024[2].

NC State Extension has also developed a short training course to assist operators in ensuring digesters are operated as designed, and minimize safety and operational risks. This training will be rolled out to Extension agents first during Fall 2023 and will be available as part of operator in charge (OIC) training in Early 2024.

For inquiries regarding this program or for questions regarding this technology, please contact Sharara, assistant professor and Extension specialist via email.

Sources

[1] U.S. Environmental Protection Agency. AgSTAR Livestock Anaerobic Digester Database; United States Environmental Protection Agency: Washington, DC, USA, 2023. Available online: (accessed on Sept. 25, 2023).

[2] N.C. Division of Water Resources (NC DWR). 2024 Animal Feeding Operations General Permits; NC DEQ, 2023. Available online.