Tools for Emission Inventories

Important Note on TANKS Program

The EPA's TANKS emissions estimation software is no longer the best available source for estimating emissions from storage tanks. The TANKS software is known to have errors and was developed using a software that is now outdated.

Therefore, the recommended method for estimating these emissions is to use the equations/algorithms specified in AP-42 Chapter 7 for estimating VOC emissions from storage tanks. The equations specified in AP-42 Chapter 7 can be found here.

Oklahoma Department of Environmental Quality has developed a tool that can be used to estimate working and breathing losses from volatile organic liquid storage tanks. This tool incorporates EPA’s updated AP-42 calculation methodology which replaced the outdated TANKS emissions estimation software.

 Air Emissions Reporting On-line (AERO)

The link below is accessible by facilities required to provide an emission inventory update as defined in a notification letter mailed from the Division of Air Quality. Access is provided to the Air Emissions Reporting On-line (AERO) website by clicking the link above. Authorized (by Responsible Official) facility staff must use the User ID and PIN sent in the notification letter that defined the inventory requirement. From this web page, instructions are provided to download and print the required forms that have been pre-filled with facility information from DAQ's database or to access the on-line update capability.

Help screens and links to a Comments field are provided throughout the system. Facility staff and representatives should also feel free to call the emission inventory contact at the appropriate DAQ Regional office for more information or help in navigating the online submittal process.

Data submitted via this web site will be reviewed by DAQ before being accepted as "approved." Submittal of complete documentation of calculations and the certification of accuracy signed by the facility's Responsible Official are also required before the inventory may be approved.

Access AERO

General Information Form

Historically, general facility information was updated when the emission inventory was provided. It is now due any time the related information changes. This one-page form may be used for submitting updates to company name, addresses, contacts, telephone numbers, etc., when these changes occur.

Download form (.doc)

Eventually, this form will likely be supplemented or replaced by a web page that will allow these updates to be made electronically. Also, there are other avenues, such as a permit renewal or application, that may result in the same information being updated to DAQ. If this information is being updated by other means, only one submittal should be necessary for the corrections to appear across DAQ's databases.

Air Permit Renewal Form

Many Emission Inventories are submitted along with Air Quality Permit Renewals. If no alterations or modifications have been made to the currently permitted sources, you may apply for renewal, by submitting one original copy of application Form A.

Air Quality Permit Forms

Emission Estimation Spreadsheets  

Use these spreadsheets developed by the NC DAQ Permits Section, to aid in the calculation of emissions.

Emission Estimation Spreadsheets

Introduction to EPA's Compilation of Air Pollutant Emission Factors

Find pertinent background and information related to estimation of emissions and appropriate use of the information. Factors for specific industries may be found by following the outline.

AP-42: Compilation of Air Emission Factors

Table of Pollutants

These tables are provided for for North Carolina Emission Inventory and permitting purposes. Please note that the lists of HAPs and TAPs from the Clean Air Act and in NC Rules, respectively, are the final authority and this list is primarily for user convenience and consistency of forms and formats. 

This list is NOT to be confused as a listing of all VOC or particulate matter compounds that are to be reported under those "criteria" pollutant definitions. Further listing of VOCs that are not HAPs or TAPs, that are excluded from reporting for reasons of photochemical reactivity are listed in the instructions for the inventory. Exclusion from reporting as a photochemically non-reactive VOC does not exclude them from being reported as a HAP or TAP.  Note that minor corrections to the grouping of pollutants were made on May 16, 2019 to pollutant list.  

Table of Pollutants (EXCEL)                           Table of Pollutants (PDF)

  • Tables of Air Pollutants for North Carolina Emission Inventory and Permit Purposes has TABS for:
    • Criteria Pollutants (Revised March 15, 2005)
    • Hazardous and Toxic Air Pollutants (Revised March 22, 2022, Effective February 4, 2022, EPA added 1-bromopropane added to the HAP list)
    • Groups of Hazardous Air Pollutants and Lists of Common Constituents (Revised May 16, 2019)
    • Other Non-Criteria, Non-HAP, Non-TAP Pollutants Required to be Reported in the Emission Inventory (Revised May 16, 2019)
    • Greenhouse gas (GHG) pollutants that can be voluntarily reported (Revised February 27, 2020)
  • Introductory Text and Log of Revisions (Revised February 9, 2009)
  • Glycol Ether Searchable Database

Source Classification Code (SCC)

A Source Classification Code, or SCC, is an eight-digit number that EPA uses to classify various industrial sources for purposes of relating to emission factors, grouping common "kinds" of sources. Each SCC represents a unique source category-specific process or function that emits air pollutants.

The codes are broken down as follows:
    First digit = broad source description category
    Next two digits = industry or type specific description
    Next three digits = source type and/or raw material, and
    Final two digits = specific source type and units of throughput
(Note: future versions or updates of SCC's will likely have "units" as a separate entity)

An Introduction to Source Classifications Codes can be found here

To search EPA's most updated SCC list, use the link below:

SCC Search