Any business in Colorado that emits air pollution may be required to report its emissions and/or apply for a permit. Submitting an Air Pollutant Emissions Notice (APEN) is required to report your emissions, apply for a permit, or modify a permit.
Your APEN will be rejected if it is filled out incorrectly, is missing information, or lacks payment for the filing fee. The re-submittal will require a new filing fee. See our Application Rejection Frequently Asked Questions page for more information.
Do you need an APEN or air permit?
- Introduction to APENs video.
- Detailed guidance for calculating your emissions.
- APEN/permit threshold table.
- Ozone non-attainment area boundaries.
- Common APEN and air permit exemptions.
- APEN update guidance.
What are the fees?
Permits
Find forms to apply or modify (including APENs), and permitting process guidance.
Oil & gas APENs
If you just need an APEN and are not applying for a permit.
General Permits
General permits offer a streamlined approach, they're available for land development activities, diesel engines, natural gas RICE engines and other oil and gas operations. Sources that can meet the criteria of emissions limitations and other operating conditions may qualify for a general permit.
Administrative changes
Cancel, change ownership or company name, provide notice of startup, alternate operating scenario, relocation notice, or self-certify.
Resources
- Air permitting guidance memos
- Compliance and enforcement
Resourcesfor emissions calculations and monitoring. - Oil & gas compliance and recordkeeping
Forms and guidance for LDAR, AIMM, Regulation 7, visible emissions, NSPS OOOO, STEM, etc., specific for oil &, gas operations. - Index (oil & gas only)
APENs, other forms, and guidance. - Contacts
Permitting and compliance.
Permits
Find APENs and resources to apply for, modify or renew a permit
Administrative changes
Cancel, change of ownership or company name, provide notice of startup, alternate operating scenario, relocation notice, or self-certify.
Resources
-
Compliance and enforcement
Resources for emissions calculations and monitoring. -
Index (non-oil & gas)
APENs, other forms, and guidance. -
Contacts
Permitting and compliance.