Air Resources and Publications

Opportunity for public comments.

Guidance Documents

  • Licensing Acronyms - A list of acronyms/abbreviations that may be used in processing Air Emissions Licenses.
  • NESCAUM BACT Guidance - Guidance for determining BACT from the Northeast States for Coordinated Air Use Management (NESCAUM)
  • State of Maine BACT Guidance - Summary of general requirements when preparing a BACT analysis for the Maine DEP
  • Construction Guidance – Information on what construction activities may take place prior to issuance of an air emission license.
  • Changes to 38 MRSA §603-A - Guidance regarding changes to sulfur content in fuel oil
  • Distillate Fuel Transition - Guidance for storage terminals and distribution facilities regarding the transition to 15 ppm distillate fuel.
  • NMMPP FAQ - Frequently Asked Questions about Nonmetallic Mineral Processing Plants (Rock Crushers)
  • Temporary Insignificant Activities - Guidance on what equipment is eligible to be considered a temporary insignificant activity and the process for requesting approval
  • Clean Air Act Section 176A Petition – Frequently Asked Questions about implementation of Maine’s approved Clean Air Act Section 176A Petition

Guidance Specific to Engines

  • Inclusion in Applications - When to include portable engines in Air Emission License applications.
  • Modeling Guidance - When to exempt stationary internal combustion engines from a modeling analysis if used for maintenance, stand-by, or emergency use.
  • QAISA Guidance - When and how to submit a Qualitative Ambient Impact Screening Analysis (QAISA) pursuant to Chapter 169.
  • Very Small Engines - Guidance on requirements for stationary engines smaller than licensing thresholds
  • Mineral Processing Industry Engines – Article on the difference between stationary and portable engines.

Additional Compliance Resources are available on our Air Compliance webpage.

Reports