To apply for a new permit or modify an existing permit, follow these steps.
1. Choose the appropriate APEN below, if you do not see an APEN that fits your operation or equipment use the General APEN form.
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.
Use this form to report boilers, hot oil heaters, process heaters and other similar equipment.
Use our boiler emissions calculator to calculate emissions for boilers rated under 100MMBtu.
Spark Ignition Engine APEN: Form APCD-201.
Calculate your natural gas-fired engine emissions.
General permits offer a streamlined approach. Sources that can meet the criteria of emissions limitations and other operating conditions may qualify for a general permit.
Compression Ignition Engine APEN: Form APCD-233.
Diesel engine that are subject to New Source Performance Standard Subpart IIII must submit the APEN Addendum Form APCD-214 along with the engine APEN (Form APCD-233).
General permits offer a streamlined approach. Sources that can meet the criteria of emissions limitations and other operating conditions may qualify for a general permit.
Calculate emissions for diesel engines:
Grain elevators & feed mills APEN: Form APCD-230.
Use this form for:
- Food/beverage processing plants that handle grain.
- Large grain elevators and feed mills.
- Pet food manufacturing plants.
Report grain handling activities, including receiving, shipping, storage, cleaning, milling, grinding, handling (headhouse, elevators, conveyors), drying, flaking, or cooling.
Land development APEN: Form APCD-223.
Use this form for various development activities including excavation, grading, paving, etc.
You don't need to submit this form for projects fewer than 25 acres and less than six months. This form is not for sources that will operate for an indefinite period.
Guidance document for land development APEN.
General permits offer a streamlined approach. Sources that can meet the criteria of emissions limitations and other operating conditions may qualify for a general permit.
Mining operations APEN: Form APCD-222.
This form is for sand and gravel pits and surface coal mines.
Use the Crushers and screens APEN: Form APCD-221 to report crushing, screening, or other equipment operating at the site.
Surface coating and solvent usage APEN: Form APCD-226.
- Cleaning solvent
- Coating
- Painting
- Volatile materials usage operations"
2. If you do not have one of the sources listed above, complete the General APEN
3. Complete the application completeness checklist.
4. Include any applicable APEN supplement forms:
5. Mail your complete application and payment to:
Colorado Department of Public Health & Environment
APCD-SS-B1
4300 Cherry Creek Drive South
Denver, CO 80246-1530
Fees may be paid by:
- Submitting a check with the mailed in application
- As of October 1, 2022, the Air Division no longer accepts Credit Card Authorizations through standard mail, email, or over the phone. If you need to pay APEN filing fee(s) and General Permit fee(s) with a credit card, you may use the Division’s online payment portal. If this is your first time using the payment portal, please follow the instructions in this guidance document.
Pay the APEN filing fee for each APEN submitted. More information about our fee structure is on our emissions and permitting fees page.