Emissions Inventory

2018 Emission Inventory Surveys Distributed
Annual Series of Workshops Concluded
Emissions inventory workshops to provide assistance in completing calendar year 2018 annual emissions surveys have been concluded.

A new series of workshops will be announced in early 2020 for facilities that need help completing 2019 annual reports. If you have questions regarding emissions inventories please call 602-506-6790 or email EmissionsInventory@maricopa.gov for assistance.


The Maricopa County Air Quality Department's (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 sources and provides data to county, state, and federal agencies.

A point source emissions inventory shows annual air pollutant emissions for one specific business location. An emissions inventory may be requested by MCAQD of any facility with an air quality permit in Maricopa County. At the beginning of each year, the EI unit distributes reporting forms and instructions for selected facilities to report their emissions for the previous calendar year.

Annual emissions inventory surveys serve a number of purposes:

  • They help determine a source's compliance with its air quality permit conditions 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 also provide a means of assessing progress in achieving reductions from existing controls.
  • They provide the basis for determining annual emission fees for Title V sources.
  • Inventory data are used as input for air quality modeling to demonstrate attainment of national ambient air quality standards (NAAQS).

Page reviewed 29 May 2019