The Michigan Department of Environment, Great Lakes, and Energy (EGLE) recently announced a public comment period for two proposed air permit applications submitted by the Arbor Hills Landfill. Air permits or Permits to Install (PTIs) are required when companies install or modify equipment with the potential for regulated air emissions. The Arbor Hills permit applications are for equipment that is required as part of a civil settlement (Civil No. 5:21-cv-12098-SDD-EAS) between Arbor Hills Energy (AHE) and the USEPA, USDOJ, and EGLE to settle years of ongoing environmental violations at the AHE landfill gas-to-energy plant. The most significant violation was for excess sulfur dioxide (SO2) emissions which was first cited in 2015 and will continue until this equipment is operational.
Overall, these permit applications[1],[2] represent a positive step for the landfill and the surrounding community. The proposed changes will reduce sulfur dioxide (SO2) emissions, establish emission limits, and require periodic testing to verify that SO2 emission reductions are achieved. The existing landfill gas-to-energy plant will become an energy peaking facility; idled except for during periods of peak energy demands when DTE requests additional energy production to support the electrical grid.
RNG plants offer higher revenue potential for landfill operators compared to landfill gas-to-energy plants with lower air emissions. This is because RNG can be injected directly into natural gas pipelines and sold as a commodity, whereas gas-to-energy plants burn landfill gas to generate electricity that must be sold to a utility. Large utility-operated energy plants typically generate electricity far more efficiently than the existing landfill gas-to-plant. Also, the existing landfill gas-to-energy plant has been cited by EGLE as the source of unauthorized releases of landfill gas.
Fig 1 - Example of RNG Plant
The higher gas revenue is paying dividends for Salem Township as they are in the process of negotiating a new Host Community Agreement which will increase revenues paid to Salem Township by at least 25% for the next 15 – 20 years. The landfill has paid Salem Township an average of $150,000 per month since January 2022. This fee will increase to at least $200,000 per month when the RNG plant is operational.[3] (You’re welcome!)
Air permits can be very technical documents that can require time to negotiate and detailed air modeling to verify there will is no potential for significant deterioration of the ambient air quality in the surrounding community prior to the permits being approved. Air permits are construction permits and are required before construction begins. Arbor Hills Energy was issued a Violation Notice in August 2022 for beginning construction of the RNG plant and ancillary equipment long before these permits were completed. We will remind EGLE and the Attorney General of this disregard of their authority when negotiating future permits or settlements with Arbor Hills.
The Conservancy Initiative is conducting a detailed review of the draft permit conditions and expects to submit comments to EGLE during the comment period. We encourage all residents to attend the virtual public hearing scheduled for May 18, 2023, and anyone with comments on the permits to submit the comments in writing before the end of the comment period. <CLICK HERE> for a link to the Public Comment Period and the Public Hearing.
[1] Permit application APP-2022-0214 is for the proposed installation and operation of a renewable natural gas plant (RNG) for Emerald RNG, LLC & Arbor Hills RNG, LLC.
[2] Permit application APP-2022-2015 is for the proposed treatment and restriction of the landfill gas burned in the existing turbines for Arbor Hills Energy, LLC.
[3] Third amendment to host agreement and lease, Arbor Hills Landfill and Township of Salem, source: Salem Township Board of Trustee meeting package, April 11, 2020, pages 64 - 67