An emissions inventory (EI) is an accounting of all air pollutant emissions actually released into the atmosphere. This accounting forms the basis for air quality planning that occurs at county, state, and national levels. Pursuant to Arizona Administrative Code (A.A.C.) R18-2-327, any source subject to a permit may also be required to complete and submit an annual Emissions Inventory Questionnaire (i.e., Reporting Form) to ADEQ.

A.A.C. R18-2-327 | View >

Does my Facility Need to Report?

Some, but not all, ADEQ air permit holders are required to report their 2024 emissions to ADEQ.

• Class I permit holders are required to report emissions annually.
• Class II permit holders are required to report at least once every three years, but may be required to report more frequently at the Director’s discretion. 
• You may still be required to report emissions even if your permit is now closed.

If you are unsure whether you are required to report your 2024 emissions, please consult the reporting guide | View Guide >

EI Reporting Forms

If you are required to report a 2024 emissions inventory, your report must be submitted by June 1, 2025, via one of the following methods: 

• If you did not operate the entirety of 2024, use the Non-Operational Form | View PDF >
• If ADEQ has enrolled you in the Combined Air Emissions Reporting System (CAERS), report via CAERS | View User Application >
• If you operate under a rock product general permit, the year-end permit compliance certification process in myDEQ includes the review and certification of an EI report for the preceding year. Year-end compliance certifications must be completed in myDEQ each January. No additional annual EI reporting is required once that process is complete | Log In to myDEQ > | How to Get a myDEQ Account >
• All other reporters should complete the preferred reporting form workbook per its README instructions | Download XLSX >
• If you do not have access to spreadsheet editing software, a PDF version of the workbook is available. You are not required to fill in the shaded bottom row of each worksheet | View PDF >

Facilities should submit completed, signed PDF and/or Excel forms via email | Email >

Emissions Inventory Training

Help Videos

• US EPA training videos for CAERS | Visit EPA Website >  
• Preferred (.xlsx) reporting form | Coming soon
• Rock product general permit EIs | Coming soon

Workshops

• EI reporting workshop for reporters using the Combined Air Emissions Reporting System (CAERS): 
  • Date: April 24, 2025
  • Time: 10:30 – 11:30 a.m. (MST - Arizona)
  • How to Join: Online via Zoom | Register >
    After registering, you will receive a confirmation email containing information about how to join the webinar. If you are unable to attend Zoom events, please use the call-in information provided in the confirmation email.
• 2024 ADEQ Annual Emission Inventory Reporting Workshop for Submission by Preferred Reporting Forms or by myDEQ | View Presentation > | Watch Video >
• 2024 ADEQ Annual Emission Inventory Reporting Workshop for Submission by CAERS | View Presentation > | Watch Video >

Online Consultations 

ADEQ welcomes emission inventory reporters to schedule one-on-one online consultations with our staff. During the consultation, we can address emission inventory questions, clarify requirements, discuss inventory preparation and submission best practices, troubleshoot errors, etc. | Book a Consultation >

Guidance Documents

• Frequently Asked Questions | View > 
• Cooling towers and the preferred (.xlsx) reporting forms | Download (.docm) >
• Supporting documentation in a CAERS report | View >
• Pipeline gas compressor station EI reporting | View >
• Municipal solid waste landfill EI reporting | View >
• Utility electric generating unit EI reporting | View >

Subscription to ADEQ's EI Mailing List

For more information, join our email list. When selecting subscription topics, select Air Quality, proceed to the next page(s), select Other Air Quality Topics and then select Annual Emission Inventory Questionnaire where listed | Subscribe >

Questions?

Please email the inventory team | Email >