Emissions Inventories

The Emission Inventory Branch of the Air Division develops and manages air emission inventories for air quality planning, analysis and permitting. An air emission inventory represents the type and amount of air contaminants that are released from different sources. Several different types of inventories are maintained for these purposes.

Point Source Inventories

Emissions from major commercial and industrial sources, also referred to as point sources, are quantified when facilities are permitted. The Air Division maintains an inventory of these emissions and can provide this information for Prevention of Significant Deterioration of Air Quality (PSD) modeling and other air quality analysis purposes. If a project requires modeling, please also contact the Environmental Permits Division to ensure the modeling follows the proper protocols.

To request inventory information for PSD modeling, please contact a member of the Emissions Inventory Group.

The following information will be needed:

  • Site latitude/longitude coordinates
  • Site address
  • Radius of inventory
  • Pollutants that are needed
  • When the inventory is needed
  • Your name and phone number
Emissions Reporting- Air Emissions Reporting Requirements (AERR)

MDEQ is required by EPA to report actual air emissions for Title V facilities on a periodic basis. All Title V facilities have to report every 3 years. The next full reporting year will be 2014. In addition some large sources have to report every year. The emission thresholds for the annual reporting sources is 2500 tons per year of Carbon Monoxide (CO), Nitrogen Oxides (NOx) or Sulfur Dioxides (SO2 ) or 250 tons per year of Particulate Matter (PM), Volatile Organic Compounds (VOC), or Ammonia (NH4). If the facility meets or exceeds these limits then they are required to complete the AERR every year. If a Title V facility doesn’t meet these criteria then it is required to submit an AERR every 3 years. A request will be mailed out by DEQ in April of the year after the reporting year (i.e. April 2015 for reporting year 2014). For more information about the AERR contact the emission inventory group.

Mobile and Area Source Inventories

The Air Division develops an inventory of emissions from cars, trucks, boats, construction equipment and other non-stationary equipment, referred to as mobile sources, and minor commercial facilities and residences, referred to as area sources. While these sources of emissions are not directly regulated by the Department of Environmental Quality, they can have a significant impact on air quality.


Air Pollutant Emissions Trends – EPA emissions summaries and reports for the entire United States

Air Emission Sources website – EPA air emissions website with general summaries

National Emissions Inventory – EPA Air emissions website with detailed reports

Office of Transportation and Air Quality – EPA information on mobile emissions sources