Reclassification of HAP Major Sources as Area Sources

15 October 2020

The U.S. Environmental Protection Agency (US EPA) has finalized its proposal to revise the 40 CFR Part 63, Subpart A General Provisions to include requirements for facilities that want to reclassify from a major source of hazardous air pollutants (HAP) to an area source.

With this update, the organization has formally reversed its longstanding “Once In, Always In” (OIAI) policy and coined a new acronym: Major Maximum Achievable Control Technology (MACT) to Area (MM2A). The current administration determined that the OIAI policy is not consistent with a plain reading of the Clean Air Act because the definitions of major source and area source lack any reference to the compliance date of major source requirements. In addition, there is no other text that indicates a time limit for changing between major and area source status.

Below are a few changes that have been finalized, and will be published shortly:

  • A major source can become an area source at any time by reducing its emissions of, and potential to emit (PTE), HAP to below the major source thresholds.
  • Until the reclassification to area source status becomes effective, the source remains subject to the major source requirements. After the reclassification becomes effective, the source is subject to any applicable 40 CFR Part 63 area source requirements.
  • A major source that becomes an area source must meet applicable 40 CFR Part 63 area source requirements immediately.
  • A major source that becomes an area source and then later becomes a major source again must comply with applicable major source MACT requirements immediately.
  • Reclassification does not absolve a source subject to enforcement action or investigation of any compliance obligations.

The policy change is meant to provide a mechanism for sources to reduce their regulatory burden and an incentive for facilities to implement pollution prevention measures or enhanced air pollution control technologies to reduce emissions to below major source levels.

Details Courtesy of ALL4.