Emission Inventories Frequently Asked Questions

The list below are some of the most frequently asked questions about AERO and submitting emission inventories.  If you do not see your question listed here, please contact your Regional Office contact or Tammy Manning ( tammy.manning@ncdenr.gov ).  

  1. Why are there already data in AERO when I open it?
  2. Can I change my PIN Number?
  3. When should I use or am I required to use EPA's newly published AP-42 emission factors?
  4. Why do I get white screens and other problems in AERO?
  5. Where are the de minimus values for each pollutant?
  6. Is it necessary to use the auto-calculation feature of AERO; and if not how do I input externally calculated emissions?
  7. Can I print completed forms prior to submittal?
  8. What must I submit with my inventory?
  9. Will the facility receive confirmation that forms have been received by NCDAQ?
  10. My facility was Title V, but either became inactive or changed to a Synthetic Minor or Small permit class during the Calendar Year subject to the Emission Inventory. Do I still need to prepare and submit the Emission Inventory?
  11. I do not see a link to the Certification form on the Closeout tab in AERO. Can I get a copy of this form in AERO?
Here are the answers to the questions:

1. Question: Why are there already data in AERO when I open it?

Answer: The data in AERO when you open it are the Equipment/Emission Source and Control Device ID's and descriptions that have been entered by DAQ from the facility's permit. Also Operating Scenario-level data from the previous submittal will be included in the information uploaded to AERO.

2. Question: Can I change my PIN Number?

Answer: Yes. Click the 'Reset PIN' button on the login page. On the page that comes up, you will have to enter your userid, current PIN and the new PIN twice. Then click the Logon button and enter your emission inventory data.

3. Question: When should I use or am I required to use EPA's newly published AP-42 emission factors?

Answer: The facility is required to use the "best available" information to estimate emissions. If the EPA's AP-42 factors are determined to be acceptable as best available information, then the latest factors, including newly issued, are to be used. However, if the issuance of new AP-42 factors is within 4 months of the due date for an inventory for the previous year, then the facility is required to use the new AP-42 factors (assuming they are applicable to the operating scenario).

4. Question: Why do I get white screens and other problems in AERO?

Answer: There may be a system problem that needs to be reported via the link provided. However, we are finding that often users of the system have not adhered to the system requirements outlined in the login screen. More specifically, use of a browser other than Internet Explorer 8 or 9 will frequently result in white screens or inability to "see" certain pages properly. The User may need to update their browser (usually free downloads from the vendor) to a later version. If the user is running IE10 or IE11, these versions of Internet Explorer will need to be run in compatibility mode which can be found under Tools. Google Chrome and Firefox browsers seem to cause issues with viewing of AERO screens. In addition, other minimum specifications of the hardware may be limiting.

5. Question: Where are the de minimus values for each pollutant?

Answer: The de minimus (minimum reporting threshold) values are reported in the 'Tables of Hazardous and Toxic Air Pollutants for North Carolina Emission Inventory and Permitting Purposes' on the DAQ Emission Inventory web page. The individual pdf files for the facility should also have the value for each pollutant reported in the previous inventory on the Facility Summary Report/Form. The de minimus applies to the facility total for a specific pollutant and not to the individual emission source/operating scenario.

6. Question: Is it necessary to use the auto-calculation feature of AERO; and if not how do I input externally calculated emissions?

Answer: It is not necessary to use this auto-calculation feature. If you input a emission factor, the system assumes that you wish to calculate emissions and multiplies the emission factor you entered by the throughput for this operating scenario (must be in same units) and utilizes the control device efficiency information to calculate emissions. If you do not wish to use this feature, just enter the emissions data in the emissions column, leave the emission factor blank, and be sure to document emission factor justification in the documentation. The entry of a factor will override any entry into the emissions field.

If you have a situation where the emission factor you are using is "after controls" (i.e. already reflects the control efficiency of the device used for the specific pollutant, enter the control device efficiency and change the column to "after" so that the system does not calculate control device efficiency again.

7. Question: Can I print completed forms prior to submittal?

Answer: Yes. Select the Closeout tab at top of page, scroll down to bottom of page and select Print Complete Emission Inventories as Entered in AERO.

8. Question: What must I submit with my inventory?

Answer: If the emission inventory is submitted through AERO, the documents required to be mailed to DAQ are an original of the certification form with the date and time of submittal stamped on the top of the form signed by the responsible official in blue ink and one copy of documentation/calculations. If you need to update your facility contacts then also submit the General Information form. To get the Certification form, after submitting your emission inventory to NCDAQ, select the Closeout tab at top of page, scroll down to bottom of page and select Certification and Emission Inventory Forms as entered (Copy of Record). To get the General Information form, select the Closeout tab at top of page, scroll down to bottom of page and select Print General Information Change form.

9. Question: Will the facility receive confirmation that forms have been received by NCDAQ?

Answer: Yes. DAQ has implemented automated email confirmation informing you of successful completion of this process in AERO. Therefore, it is important that your email address is entered correctly on the Contact page. If you do not receive an email within 24 hours of submitting your emission inventory, please check the Closeout Tab in AERO for a note at the top of the page in red stating the emission inventory has been submitted and cannot be changed. If you do not see this notation, please resubmit the emission inventory using the 'Submit to NCDAQ' button. If the notation is visible, please call your regional office contact for assistance.

10. Question: My facility was Title V, but either became inactive or changed to a Synthetic Minor or Small permit class during the Calendar Year subject to the Emission Inventory. Do I still need to prepare and submit the Emission Inventory?

Answer: Yes (for one year). If a facility was TV any time within the year and changed to a lower category or went inactive during the year of the inventory, they are still required to provide us with a "close-out" inventory. This is needed for various modeling, compliance and federal reporting purposes. The final inventory has been viewed as a legal "liability" in cases where a facility is settling a sale, a bankruptcy, etc. and has been successfully pursued by the AG's office. However, peculiar things can happen in remote circumstances which may cause rare exceptions to this making sense. Just be wary and discuss with your regional Supervisor should there be a question.

After one non-TV report, the facility falls into the normal inventory cycle beginning with the next year of "non-TV" inventories.

11. Question: I do not see a link to the Certification form on the Closeout tab in AERO. Can I get a copy of this form in AERO?

Answer: In order to meet the requirements of NCDAQ's Cross-Media Electronic Reporting Regulation (CROMERR) application for AERO, the certification form has to have the same date and time stamp as the emission inventory forms associated with it. Therefore, the certification form cannot be generated until after the data is submitted. Once the 'Submit to NCDAQ' button has been clicked, there will be a link to the Certification and completed emission inventory forms on the Closeout tab in AERO.