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 requirement may also be required to complete and submit an annual Emissions Inventory Questionnaire 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. 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 download and consult the reporting guide | Updated Guide Coming Soon

For ADEQ rock products air general permit holders only:

Your 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 >

However, if you believe that the emissions estimates included in the myDEQ compliance certification are inaccurate and you would prefer to submit a separate report to supersede them, please follow the Class II permits reporting instructions below.

EI Reporting Forms

If you are required to report a 2024 emissions inventory, your report must be submitted by June 1, 2025. Facilities reporting using PDF or Excel forms should submit the completed, signed forms via email | Email >

Class I permits

• All class I air permit holders, as well as any operations which previously reported an EI to ADEQ using the State & Local EI System (SLEIS), must now report via the Combined Air Emissions Reporting System (CAERS). See the user application form or email us for additional details | View > | Email >

Class II permits

• Class II permit holders are only required to report once every three years or at the Director’s discretion. View the reporting guide to determine if you need to report your 2024 emissions | View Guide >
  Please email us with any questions | Email >
• If you were non-operational for the entirety of 2024, use the Non-Operational Form | View PDF >
• Otherwise, complete the preferred reporting form workbook per its README instructions | Download XLSX >
• If you do not have access to spreadsheet editing software, an alternative PDF version of the reporting workbook is available. You are not required to fill in the shaded bottom row of each worksheet | View PDF >

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

• 2025 ADEQ Annual Emissions Inventory Reporting Workshop will be held in April 2025. Subscribe below to ADEQ’s EI Mailing List to be notified once the workshop is scheduled.
• 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 >