Instructions, References and Help for Completing an Oklahoma Air Emissions Inventory. If you need further help or have a question that cannot be answered by the information available here, then please contact the Emissions Inventory Section.
AP-42 – AP-42 refers to the EPA’s Compilation of Air Pollutant Emission Factors, a series of representative values that attempt to relate the quantity of a pollutant released to the atmosphere from a particular activity.
CHIEF – EPA’s Clearinghouse for Inventories & Emissions Factors (CHIEF) is an excellent resource for all aspects of emissions inventories.
WebFIRE – WebFire is EPA’s online emissions factor repository, retrieval, and development tool. The WebFIRE database contains EPA’s recommended emissions factors for criteria and hazardous air pollutants (HAP) for industrial and non-industrial processes.
Source Classification Codes (SCCs) – Searchable database to find which SCC represents an emissions process or activity. EPA uses SCCs in databases such as WebFIRE and the National Emissions Inventory (NEI).
NAICS– This page includes a searchable list for North American Industrial Classification System (NAICS) codes for business establishments. This official U.S. Government Web site provides the latest information on plans for NAICS revisions, as well as access to various NAICS reference files and tools.
SIC– Use this page to determine a Standard Industrial Classification code for a facility
Annual Operating Fees
All facilities that are sources of air pollution, regardless of whether the source is currently permitted or an emission inventory has been submitted, are required to pay annual operating fees. Exceptions include permit exempt and de minimis facilities. Additional information on fees can be found in OAC 252:100-5-2.2.
Total VOC is split into HAP and non-HAP VOC for billing.
CO is not billed.
Fees are calculated two years in arrears.
When calculating annual operating fees for facilities that are registered under Permit by Rule (PBR), the last reported inventory emission amounts are used.
Invoice
Invoices are sent annually to companies with 5+ tons of billable emissions on the first business day in July.
Facilities that cease operations are still responsible for payment of operating fees based on emissions reported when in operation.
New owners of facilities assume payment liability for the operating fees which can be based on emissions reported in the years of operation prior to transfer of ownership.
Inventory amendments with a 5+ ton increase in billable emissions may result in an adjusted invoice. Processing is done annually, separate from the annual July invoice.
When sources are invoiced, whether from an initial inventory or amended inventory, the fees will be assessed at the most current year rate at submission.
Fee Determination
Title V (Part 70) source fees were set at $32.30 per ton of regulated air pollutant in 2008. The fee is adjusted each year based on the change in the annual Consumer Price Index (CPI) at the end of August relative to the 2007 CPI.
New: Minor source fees were set at $36.50 per ton of regulated air pollutant as of July 1, 2024. The fee is adjusted each year based on the change in the annual Consumer Price Index (CPI) at the end of August relative to the 2024 CPI.
The 2025 minor source fee was $36.50 per ton; the 2026 minor source fee will be $37.56.
The 2025 Title V fee was $48.90 per ton; the 2026 Title V fee will be $50.33.
Additional information on fee calculations can be found in OAC 252:100-5-2.2.
Frequently Asked Questions (FAQs)
Who must submit an Emissions Inventory?
Subchapter 5 (OAC 252:100-5) requires owners or operators of any facility that is a source of regulated air pollutants to submit an emission inventory through DEQ’s electronic reporting system or in another manner acceptable by the Division. The owners or operators of permit exempt facilities or de minimis facilities, as these terms are defined in OAC 252:100-7-1.1, are not required to submit an annual emission inventory unless annual emissions from the facility exceed any of the emission thresholds listed in Table 1 in Appendix A to Subpart A of 40 CFR Part 51.
How often should an Emissions Inventory be submitted?
An annual inventory is required every year, with the exception of facilities registered under a permit by rule (PBR). The Oklahoma Administrative Code rule regarding emission inventory reporting for PBRs is included below.
(2) Permit by rule. The owner or operator of a facility registered under a permit by rule in Subchapter 7, Part 9, shall submit, at a minimum, an annual emission inventory for the 2014 reporting year or the calendar year in which the facility is registered, if the facility is registered after December 31, 2014, and thereafter according to the following schedule:
(A) For a registered facility with actual emissions greater than 5 tons per year of any regulated air pollutant, an annual emission inventory for that facility shall be submitted for every National Emissions Inventory (NEI) Three-Year Cycle Inventory year, as defined in 40 CFR Section 51.30(b).
(B) For a registered facility with actual emissions of 5 tons per year or less of any regulated air pollutant, an annual emission inventory for that facility shall be submitted every second National Emissions Inventory (NEI) Three-Year Cycle Inventory year, as defined in 40 CFR Section 51.30(b), beginning with the 2020 NEI reporting year.
Example: When a facility obtains registration under a PBR in 2021, the facility must submit an initial emission inventory (2021). If the facility has actual emissions greater than 5 tons per year of any regulated air pollutant in 2023 (which is an NEI Three-Year Cycle Inventory year), a 2023 emission inventory must be submitted, otherwise their next report due is a 2026 emission inventory (which would be the second NEI Three-Year Cycle Inventory year).
Note: the goal of the rule is to capture the initial inventory for the facility, so if in the example the facility didn’t begin operating until 2022 then the facility would report “Not Yet Built” for the facility operating status in 2021, and then report their initial inventory for 2022.
How do I submit an Emissions Inventory?
The Oklahoma Air Pollution Control Rules in OAC 252:100-5-2.1(a) state, “The owner or operator of any facility that is a source of regulated air pollutants shall submit a complete annual emission inventory through DEQ’s electronic reporting system or in another manner acceptable by the Division.” SLEIS (State and Local Emission Inventory System) is the current acceptable electronic reporting system.
What must be submitted? Is there a minimum threshold for reporting emissions?
A lower cut-off or minimum amount of emissions of an individual pollutant that should be reported is not defined by rule. If emissions are 0.1 tons or greater of any regulated air pollutant at a process, then the emissions must be reported. The key exceptions that must be reported at 0.001 tons or greater per process are:
Lead, mercury, and chromium
Any Hazardous Air Pollutant (HAP) at a facility that is also reported to the Toxics Release Inventory (TRI)
Any HAP from glycol dehydration still vents
Any HAP from large storage tanks (>500 BBL)
Other situations where deemed necessary
Grouping Emission Units
Small sources that individually do not have reportable emissions, but collectively have emissions over the reporting threshold, should be reported. They can be grouped into one source. For example, all of the small sources at one process unit or building could be submitted together. Emergency generators can often be grouped in an inventory.
The emission unit name should include the number of units being grouped.
The release point should be reported as a fugitive with the total area of all the units and the average height.
Process rates, including maximum hourly and typical daily, should be reported as an average.
Operating periods, including the actual hours per year, should be reported as an average.
Design capacity should be reported as an average.
Actual emissions should be the sum of emissions calculated based on the actual process rate or actual hours per year of the individual units, not the averaged values.
An emission unit note should be added to further clarify the number of units being grouped and the individual design capacities (if a combustion process).
Do I need to build an inventory myself, or does SLEIS prepopulate it?
Facility information, but not equipment, will be entered into SLEIS by DEQ. Release points, control devices, emission units, processes and process emission data are required to be added by a user with the Editor role for this facility. After the first report is submitted, all the records will remain for future reporting years, even if a facility is sold to another company.
To assist in creating an inventory, SLEIS allows users to clone control devices, release points, emission units, and their related processes from one facility to another, or within the same facility, if the following criteria are met:
The receiving facility’s inventory is in an “In Process” status and therefore open for editing.
The user has the Editor role for both the receiving facility and the original facility.
April 1 after the year of operations, unless an extension is approved or the facility has a Permit By Rule (PBR) alternate reporting schedule.
Can a company obtain a list of facilities that must report?
SLEIS users may view all of their facilities that are required to report in a given reporting year by opening the SLEIS “My Companies” page, selecting “Open Reports for Batch Operations” under the “Actions” heading, and ensuring that the reporting period is set to the appropriate year. The Emission Inventory Section makes every effort to track facilities’ emissions inventory reporting requirements; however, it is the owner/operator’s responsibility to know which facilities must report. Contact us if you believe a facility is missing or for a comprehensive list that includes facilities that are not currently required to be reported.
What if my company buys or sells a permitted facility (Change of Ownership)?
It is the responsibility of the seller to submit DEQ Form 100-883 no later than 30 days following the change in ownership; this includes facilities registered under Permit By Rule during non-reporting years. Oklahoma law and DEQ rules are clear that the current owner/operator of a facility is responsible for the submission of the annual emissions inventories and for paying the annual operating fees, including inventories and fees from prior year emissions. DO NOT update a facility status to Temporarily or Permanently Shutdown on your emissions inventory report if you no longer own the facility; submit DEQ Form 100-883 so that DEQ staff can transfer the facility to the new owner.
How can a permit be terminated?
A permit may be terminated when a facility permanently ceases operations or when either DEQ or the facility representatives determine that the facility qualifies for “permit exempt” or “de minimis” status as defined in OAC 252:100-7. A facility representative may self-determine the facility’s eligibility to claim either status and request DEQ terminate the permit.
A facility may terminate a permit in either of two ways.
Facilities may submit a termination request at any time during the year. Requests should be made either in writing or email and address the following:
Provide reason for termination (closure, permit exempt, de minimis)
Reference the permit number
Provide facility and company name
Provide date when facility ceased operations or became eligible for “permit exempt” or “de minimis” status
Where the facility has ceased operations, please indicate if emitting equipment has been removed or remains in place.
Call 405-702-4100 and ask to speak with permitting staff for additional guidance.
Terminations can be initiated in SLEIS when submitting an annual inventory:
If the facility closed during the reporting year but has reportable emissions for the year they closed, a complete annual inventory is required for that year. The facility must wait until the next reporting season to report the facility as Permanently Shutdown and request the permit be terminated through SLEIS.
Termination requests in SLEIS must be done by the company Responsible Official (RO) with the Submitter role in SLEIS.
A termination request in SLEIS is done during an inventory’s Submission Agreements step by certifying that the Permanently Shutdown facility had no emissions at any time during the reporting year and that the permit should be terminated effective December 31st of the reporting year.
The company Responsible Official (RO) must complete the Designation of Responsible Official / SLEIS Registration Form #100-882 and submit to the Emissions Inventory (EI) section. After the form is processed, the RO will receive an email from SLEIS with instructions on creating a password; the RO will then be able to log into SLEIS and access their company(s). ROs will be assigned the Submitter and Administrator roles, and either a Viewer or Editor role. These roles are explained in detail on the first page of the form. Consultants are not eligible to serve as ROs.
Individuals that require a SLEIS account but are not an RO should complete the #100-733 SLEIS User Registration Form. This form should be signed by the SLEIS company RO and submitted to the Emissions Inventory (EI) section. Once processed, the User will receive an email from SLEIS with instructions on creating a password; they will then be able to log into SLEIS and access their company(s). Users will be assigned either a Viewer or Editor role, with the option be added as an Administrator. These roles are explained in detail on the first page of the form.
Can more than one person in our company use SLEIS or be designated as an RO?
Yes, SLEIS may have multiple account holders for companies or facilities, including more than one RO. All users must fill out the appropriate DEQ form requesting access to SLEIS. When sending in a Designation of Responsible Official / SLEIS Registration Form #100-882, please let us know if the new RO will be replacing the current RO or if the person will act as an additional RO. Other company individuals who do not meet the qualifications of an RO may be appointed as a Duly Authorized Representative (DAR). They can be assigned a SLEIS Submitter role by completing a #100-882 form with their signature and submitting the form with an accompanying letter or email, originating from the current RO, authorizing them as a DAR.
Does the Responsible Official (RO) have to physically sign the final submission when using SLEIS?
No. The RO does not need to physically sign the final submission when using SLEIS. Under Oklahoma Statute (12A O.S. sec. 15-101 et seq.), compliance with the conditions on the SLEIS Attestation (Agreement) page results in a legally binding electronic signature.
How can a company designate or change a Responsible Official (RO)?
All supporting data, including actual production, throughput, and measurement records along with engineering calculations and other data utilized in accordance with OAC 252:100-5-2.1(d) must be maintained for at least 5 years by the current owner or operator at the facility in conjunction with facility records of the emission inventory. This information must either be submitted to the Division or made available for inspection upon request.
What if an error is discovered in our inventory?
If DEQ finds an error, a company may be required to submit corrections for inventories submitted over the past 5 years. If the company finds an error, the company need only correct inventories over the past 3 years, assuming the error occurred in all 3 years. Amendments can be requested, entered and submitted directly in SLEIS by the company. Log into SLEIS, navigate to the company, facility, and year requiring an amendment and select the “Request Amendment” selection from the right side of the screen. You will receive an email when the report is available for amending.
Reporting Requirements when converting to a Permit By Rule (PBR)
If the removal of permitted equipment causes a facility operating under an Individual or General Permit to become eligible for a Permit by Rule, the facility must still submit an emissions inventory for the year in which the equipment was removed. If the facility was eligible for a Permit By Rule the entire year (and it is not a required triennial reporting year), the facility does not need to submit an emissions inventory. The emissions inventory from the prior year will be used to satisfy the PBR reporting schedule.
Although the Emissions Inventory Section makes every effort to track facilities’ reporting requirements, contact us if you believe there is a discrepancy.