Emissions Inventory

The Maricopa County Air Quality Department (MCAQD) Emissions Inventory (EI) Unit collects, reviews, 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).

Annual Emissions Inventory Reports

MCAQD enables emissions reporting in January of each year, and email notifications are sent to the contacts for facilities that are required to submit an emissions inventory. All emissions inventory reports must be completed using the AQD Online Portal. Paper forms will not be accepted.

Before creating an emissions inventory, thoroughly review the EI instructions and help sheets and attend an emissions inventory workshop to learn about the AQD Online Portal and requirements for the current reporting period.

Due Dates

The 2022 annual emissions inventory reports were due on Sunday, April 30, 2023 at 11:59 p.m.

Contact Us

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

Page reviewed 29 September 2023