Periodic Emission Inventory Reports

Every three years the Maricopa County Air Quality Department (MCAQD) prepares periodic emissions inventory reports for pollutants.

Draft 2020 Periodic Emissions Inventory 

The draft PEI for ozone includes emission estimates for three precursors to ozone formation: volatile organic compounds, carbon monoxide, and nitrogen oxides. Annual and season-day emissions are calculated for Maricopa County, the 2008 8-hour ozone nonattainment area, and the 2015 8-hour ozone nonattainment area. 

Draft 2020 Periodic Emissions Inventory for Ozone Precursors

The draft PEI for particulate matter includes emission estimates for particulate matter less than 10 and 2.5 microns in diameter (PM10 and PM2.5), as well as three particulate matter precursors: nitrogen oxides, sulfur oxides, and ammonia. Annual and typical daily emissions are calculated for Maricopa County and the PM10 nonattainment area.

Draft 2020 Periodic Emissions Inventory for Particulate Matter

MCAQD invites the public to review the draft PEI for ozone precursors and the draft PEI for particulate matter and to submit comments to EmissionsInventory@maricopa.gov or to: 

Maricopa County Air Quality Department
Emissions Inventory Unit
301 W. Jefferson St., Suite 410
Phoenix, AZ S5004

Comments must be received no later than October 31, 2022. Interested persons may request a public hearing in writing. Requests for a public hearing must be received prior to October 31, 2022.

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 (PM)

The particulate matter emissions inventories include emissions estimates for particulate matter less than 10 microns in diameter (PM10), particulate matter 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. Periodic emissions inventories for CO were not prepared in 2011, 2014, or 2017 because Maricopa County has been redesignated as attainment for CO.

For past periodic emissions inventory reports, submit a Public Records Request to MCAQD.
Page reviewed 03 October 2022