Emissions Inventory

The Maricopa County Air Quality Department (MCAQD) Emissions Inventory (EI) Unit collects, reviews, stores, and manages air pollution emissions data for stationary sources in Maricopa County. The EI Unit also collects emission fees from Title V facilities and provides data to county, state, and federal agencies. An emissions inventory shows annual air pollutant emissions for one specific business location. An emissions inventory may be requested for any facility operating under a permit issued by MCAQD.

Annual emissions inventory reports serve several purposes:

  • They help determine a facility's compliance with its air quality permit as well as Maricopa County rules and regulations.
  • They help identify pollutant sources that may need new or additional controls, providing a basis for improved air pollution control strategies.
  • They provide a means of assessing progress in achieving reductions from existing controls.
  • They provide the basis for determining annual emission fees for Title V facilities.
  • Inventory data are used as input for air quality modeling to demonstrate attainment of national ambient air quality standards (NAAQS).

2021 Emission Inventory Report

The AQD Online Portal (IMPACT) is the Maricopa County Air Quality Department's (MCAQD) online inventory, monitoring, permitting, and compliance tracking data system. The portal currently supports Title V permits, Non-Title V permits, General permits, Asbestos NESHAP notifications and revisions, emissions inventory, and performance testing. The portal allows users to submit and track applications, reports, notifications, and documents electronically to MCAQD.

All 2021 annual EI reports must be completed using the AQD Online Portal (IMPACT). Paper forms will not be accepted. 

Please thoroughly review the EI instructions and help sheets and attend an emissions inventory workshop to learn how to access the AQD Online Portal (IMPACT) and complete your 2021 EI report.

Due Dates

The 2021 annual emissions inventory reports will be due on April 30, 2022 at 11:59 p.m. Note: MCAQD staff will be available to answer questions by phone or email until 5:00 p.m. on April 29, 2022. Any phone calls received after this time will be returned the following business day.

Contact Us

To contact the emissions inventory unit, call 602-506-6790 or email EmissionsInventory@maricopa.gov.

Page reviewed 31 March 2022