Air permits for diesel engines

If your diesel engine is NOT at an oil and gas facility, go to Air permits for non-oil & gas for applicable forms and guidance. A complete permit application for an oil & gas facility must include all applicable elements on Form APCD-100.

Diesel (Compression Ignition) Engine APEN (Form APCD-233)

Use an APEN to apply for a new permit; request a modification to an existing permit; complete a routine (five-year) renewal for an existing permitted source or report changes in emissions, production or equipment.

NSPS-40 CFR Part 60, Subpart IIII Addendum Form

Form APCD-214

For diesel engines being relocated to Colorado. Submit this form along with your engine APEN. Required only for initial applications and AOS permanent replacements.

Alternate Operating Scenario (AOS)

Report a permanent engine replacement for your engine.

General Permit

General Permits offer a streamlined approach to air emissions permitting. Review the general permit to determine if your engine meets the applicability requirements. 

GP06: Diesel Engines

Operating and Maintenance (O&M) plan

Required for all process units with emission controls at a synthetic minor or major stationary source. Visit the Oil & gas operating and maintenance plan page for guidance and more information.

The Division has not yet developed an O&M Plan template for diesel engines.  If an O&M Plan is required for your diesel engine, you need to develop your own and the Division will review it.

Calculate your diesel engine emissions

The links below will download a Microsoft Excel Spreadsheet.

Guidance for diesel engine permits