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Air Permit Applications

All sources of regulated air pollutants may need a permit from the Indiana Department of Environmental Management (IDEM). The Office of Air Quality (OAQ) issues various levels of air permits, depending on a number of factors. A source's potential to emit (PTE) is one of the most important factors in determining if a source needs a permit and what type.

If you are unfamiliar with the permit review process, it is strongly recommended that you refer to 326-IAC-2 [PDF] of the Indiana Administrative Code (IAC) for more information regarding permitting levels and requirements.

Preparing your Permit Application

A complete application will contain all the information necessary to determine permit level (normally PTE) and all rule applicability (including why a rule may not be subject).

How and where to submit your application

Always send one (1) original application packet and one (1) copy of the application packet directly to the Office of Air Quality Air Permits Administration. Please do not send your application to any other offices or individuals at IDEM, as this will delay receipt and processing of your application.

Local Library

You may need to send one (1) copy of the application to your local library if the permitting action is subject to the public notification provisions in 326-IAC-2-1.1-6 [PDF]. Refer to Part H of the GSD-01 form for additional information about this requirement.


Unless you are submitting an interim application, please do not submit any fees with your application. IDEM will send a bill to collect the filing fee and any other applicable fees as needed. Fee processing in this manner will not delay initial processing of your permit application. The Air Permitting Timeframes and Fees page provides additional information.

If you have questions regarding application fees, please contact the Office of Air Quality and ask to speak to the Air Permits Administration Section Supervisor.

Basic Application Forms

OAQ has created several forms for preparing a complete application packet. Every air permit application packet should include an Application Forms Checklist, the Application Cover Sheet, and the GSD-01 (See the list of General Source Data forms).

  • General Source Data (GSD) Forms:
    • The GSD forms are intended to gather all of the general information about the source of air pollution. For a new (i.e., Greenfield) source, it may be necessary to complete nearly all of these general forms. For an existing source that is only modifying a portion of the facility or making changes to the air permit, only those forms relating to the change are needed.
  • Process Information (PI) Forms:
    • The PI forms are intended to gather detailed information about specific processes that cause air pollution. Only those forms relating to the processes present at the source of air pollution are needed.
  • Control Equipment (CE) Forms:
    • The CE forms are intended to gather detailed information about the air pollution control devices used. Only those forms relating to the equipment used to control air pollution at the source are needed.
  • Compliance Data (CD) Forms:
    • Part 70 (Title V) sources are required to submit certain compliance related information with each air permit application submitted to OAQ

Permit application forms are available from Forms.IN.gov. A list of all currently available IDEM forms can be found on the IDEM Forms page.

Permit Renewal Information

  • Air Operating Permit Renewal Information:
    • Title V, initial FESOP, and initial MSOP Permits issued by IDEM OAQ expire five (5) years after the issuance date of the original permit. Even if a permit has been amended or modified, the expiration date remains dependent on the original permit issuance date. FESOP and MSOP renewals may have a permit term of ten (10) years. Sources will have the right to continue to operate after the expiration if a timely and complete renewal application is submitted.

Special Application Forms

Type of source and rule applicability determine whether a source will need to complete a special form in addition to the relevant basic application forms.

  • MACT Preconstruction:
    • MACT approval is required when an owner or operator proposes to construct or reconstruct an emissions unit or emissions units that are a major new affected source or major reconstructed affected source under one of the MACT standards contained in 40 CFR Part 63. The approval under 40 CFR 63.5 is only required if the proposed new or reconstructed affected source in and of itself has the potential to emit greater than 10 tons per year of a single hazardous air pollutant (HAP) or greater than 25 tons per year of a combination of HAPs.
  • BACT Analysis Application:
  • Prevention of Significant Deterioration/Emission Offset Checklist:
    • The Prevention of Significant Deterioration/Emission Offset Checklist needs to be completed by an applicant if the proposed new construction is subject to 326-IAC-2-2 [PDF] Prevention of Significant Deterioration (PSD) or 326 IAC 2-3 Emission Offset.
  • Interim Approval:
    • Certain types of sources may apply for an Interim Approval subject to the requirements of 326-IAC-2-13-1 [PDF]. This type of approval allows the applicant, under certain limited circumstances and at their own risk, to commence construction of a new emissions unit at an existing source or modification of an emissions unit at an existing source while the permit application is being reviewed.
  • Emission Credit Registry:
    • The Emission Credit Registry is a tool created to assist sources looking for emission offsets for nonattainment New Source Review (NSR) permitting.
  • Phase II Acid Rain Permit Renewal Information:

Additional Forms and Information

Please note that several options are available to sources that wish to limit their potential to emit below the major source thresholds, including the following:

  • A Federally Enforceable State Operating Permit (FESOP) issued under 326-IAC-2-8 [PDF]; or
  • A Source Specific Operating Agreement (SSOA): Source Specific Operating Agreement (SSOA) Application forms (available on the IDEM Forms page) need to be completed if the applicant is constructing a new source and elects to comply with the SSOA rules codified in 326-IAC-2-9 [PDF]; or
  • A Permit By Rule under 326-IAC-2-10 and 326-IAC-2-11 [PDF]. A Permit By Rule under 326 IAC 2-10 does not exempt the source from needing a construction permit. A new source wishing to be Permit By Rule under 326 IAC 2-10 must first get a construction and operating permit and hold the operating permit for twelve months of operation before going to a Permit By Rule. Some Permits By Rule under 326 IAC 2-11 may not need a construction permit.

If you have additional questions, or would like to schedule a pre-application meeting, contact the Office of Air Quality. If you have inquiries that are confidential in nature, want to discuss permitting options for various scenarios, need advice that is technical in nature, or need help choosing and filling out application forms, contact IDEM's Compliance and Technical Assistance Program for free and confidential assistance.

Submission of Confidential Records

All information submitted to IDEM will be made available to the public unless it is submitted under a claim of confidentiality. Claim of confidentiality must be made at the time the information is submitted to IDEM, and must follow the requirements set out in 326-IAC-17.1-4-1 [PDF]. Failure to follow these requirements exactly will result in your confidential information becoming a public record, available for public inspection. To ensure that your information remains confidential, refer to the IDEM OAQ information regarding submittal of confidential business information.

For more information on confidentiality for certain types of business information, please review Air-031-NPD Guidance for the Interpretation of the Term "Emission Data" (available on the IDEM Nonrule Policies page).

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