Periodic Emission Inventory Reports

Every three years the Maricopa County Air Quality Department (MCAQD) prepares periodic emissions inventory reports for ozone and particulate matter. To request previous periodic emissions inventory reports, visit the Air Quality Records and Data Portals webpage

Ozone Precursors

The ozone periodic emissions inventories include emission estimates for volatile organic compounds (VOC), nitrogen oxides (NOX) and carbon monoxide (CO), which are all precursors to ozone formation. Emissions are calculated for Maricopa County and both 8-hour ozone nonattainment areas. Annual and season-day emissions are provided for all source categories.

Particulate Matter

The particulate matter (PM) emissions inventories include emissions estimates for PM less than 10 microns in diameter (PM10), PM less than 2.5 microns in diameter (PM2.5), NOX, sulfur oxides (SOX), and ammonia (NH3). Emissions are calculated for Maricopa County and the PM10 nonattainment area. Annual and typical daily emissions are provided for all source categories.

Carbon Monoxide 

This inventory includes emissions of carbon monoxide (CO) for both Maricopa County and the CO maintenance area. Annual and season-day emissions are provided for all source categories. MCAQD is not required to prepare CO periodic emissions inventories for calendar years after 2008 because Maricopa County has been re-designated as attainment for CO.

Contact Us

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

Page reviewed 20 December 2023