Regulatory Alert - Municipal Solid Waste Landfills April 2020


Aegis extends this brief regulatory update:


NESHAP Subpart AAAA Municipal Solid Waste Landfills Residual Risk and Technology Review; Federal Register March 26, 2020.


This final rule determines that the requirements of this category provide an “ample margin of safety”, so no revisions to the current standards are necessary.  In addition, the rule promotes regulatory consistency for affected sources by allowing MSW landfills the flexibility to comply with the landfill gas control operations, monitoring, recordkeeping and reporting requirements of the NSPS by following the corresponding Subpart AAAA requirements.


A brief summary of revisions for consistency between the NESHAP and NSPS and for additional flexibility are provided below.

  • Reorganizes and consolidates NESHAP by incorporating major compliance requirements from NSPS Subpart SSS finalized in 2016.
  • Remove/revise SSM provisions with work practice requirement when the gas collection and control system (GCCS) is not operating and inclusion of periods when GCCS was not operating.
  • Eliminates operational standards/corrective action for nitrogen and oxygen concentrations as indicators of collection system proper operation.  Increases wellhead temperature to 145 oF for greater operational flexibility.
  • Requires enhanced wellhead monitoring seven days after first exceedence of temperature: weekly visual observations for subsurface oxidation events and monitoring of wellhead temperature, carbon monoxide, oxygen, and methane.  If elevated temperature 170 oF and CO readings, required to submit 24-hour electronic report.
  • Remove GCCS when landfill is closed, calculated NMOC emission rate less than 50 Mg/r and operated for at least 15 years.  EPA allowing choice of 15 years or demonstration that gas flows declining such that GCCS could not operate for 15 years.


Sources have up to 18 months after March 26, 2020 to begin complying with the final rule but must comply with existing requirements until they meet the Subpart AAAA requirements.

 If you would like more information or assistance with complying with the final rule, please contact Sandy Morse at smorse@aegisenv.com.


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