RELEASE: Air Permit Issued for Align RNG Biogas Processing Facility


The North Carolina Department of Environmental Quality’s Division of Air Quality has issued an air permit to Align RNG LLC for a proposed biogas gathering and processing facility in Duplin County. Based on the applicable state and federal rules and regulations, the facility will be classified as synthetic minor and will be required to comply with all applicable standards including the National Ambient Air Quality Standards.

After a comprehensive public process, including two comment periods and a public meeting and hearing, and a thorough technical review, the final permit includes several changes from the initial draft permit to address community concerns, including:

  • Hourly monitoring of the tail gas flow and hydrogen sulfide (H2S) concentration entering the “iron sponge” sulfur removal control device,
  • Daily record-keeping of the SO2 emissions from the flares,
  • An increased frequency of the analysis of the H2S concentration entering the facility to a monthly basis to account for potential seasonal variations,
  • Specifies the maximum biogas flow limit for the facility,
  • Requires an inspection, maintenance, and calibration plan for the facility’s air pollution control equipment and monitors to be submitted to DAQ for approval. 

The final permit, hearing officer’s report and related documents are available at The air quality permit applies only to the gathering facility located at 2940 NC Highway 24 West in Turkey, North Carolina. As currently proposed, the facility will not process biogas until the biogas producing animal operations receive the required permits.

DEQ is committed to fully evaluating the entirety of this project and addressing community concerns at each stage of the required permitting. Many of the concerns raised during the public process for the air permit were specific to the 19 animal feeding operations (swine farms) that plan to provide biogas to the gathering facility. Any animal operation choosing to participate in the biogas project is required to submit a permit application to the Division of Water Resources (DWR). DWR will thoroughly review each application for permit modification on a case-by-case basis and the issuance of this air permit does not indicate the outcome of the DWR permit processes. As currently proposed, the facility will not process biogas until the animal operations receive the required permits.

Given the significant public interest in the project, DWR is providing an opportunity for public comment and community engagement on the four draft permit modifications submitted so far for the animal feeding operations participating in the Align biogas processing project.

DWR is currently accepting comment on the draft permit modifications and will host a public meeting on January 26 to provide information and answer questions about the animal feeding operations permit modification applications. Additional information on how to participate in the meeting and register to speak is available here

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