Air Permitting Programs
All new sources, unless they qualify for an exemption under the Indiana Administrative Code (326 IAC 2-1.1-3), need some level of air permit prior to construction and operation. In most cases, IDEM has combined the construction and operating permit programs and will issue a permit document that serves as both the construction and operating permit.
The IDEM, Office of Air Quality (OAQ) encourages Permittees to have a pre-application meeting with IDEM. During a pre-application meeting with OAQ staff, a potential permittee can ask questions about forms that are needed to make an application complete, discuss potential rule applicability, discuss operational flexibility options, and learn how to calculate potential emissions from specific processes. To schedule a pre-application meeting, discuss pending applications, or request assistance concerning any of IDEM’s Air Permitting Programs, contact the Office of Air Quality. Basic application forms are available online via the Air Permit Application page or from the IDEM Forms page. The Air Permitting Timeframes and Fees page provides additional information on timelines and public notice requirements.
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.
Letter of Exemption
Construction and Operation of Sources that are Exempt from Permitting Requirements
An emission source is exempt from air permitting requirements if all of the emission units at the facility are exempt, as listed under 326 IAC 2-1.1-3, and the total potential to emit of all the emission units are below the thresholds listed under Title 326, Article 2, Rule 1.1-3 of the Indiana Administrative Code (326 IAC 2-1.1-3), and the total potential to emit of all the emission units are below the thresholds listed in 326 IAC 2-1.1-3. The minimum thresholds for all the pollutants listed are outlined in the registration thresholds table below. A source that submits an application that demonstrates to IDEM, or from which IDEM may determine, that the potential to emit of the source is below all the registration thresholds will be provided with a Letter of Exemption from IDEM. This is a voluntary decision on the part of the facility to apply for the Letter of Exemption. An exempt source can construct and operate without IDEM approval. The Letter of Exemption from IDEM verifies that there are no construction conditions to be met, so long as the source does not engage in further construction to expand its PTE above registration levels or beyond. The source may be subject to applicable regulations, and IDEM includes those regulations in the Letter of Exemption, as a service.
To view 326 IAC 2-1.1-3, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
Modifications/Changes at Exempt Sources
If changes made at a facility are substantial enough to increase the source’s potential to emit any regulated pollutant(s), it should register or obtain the proper construction and operating permit.
Construction and Operation of Sources Requiring a Registration
The Registrations Thresholds Table (below) displays the range of PTE thresholds for a Registration. Sources whose PTE is equal to or greater than the minimum threshold (middle column) of any one of the pollutants listed in the table, but also less than the maximum threshold (right-hand column) for all of the pollutants listed in the table must obtain a Registration from IDEM.
Modifications/Changes at Registered Facilities
When registered sources make changes, they may be exempt from additional operating requirements, they may only be required to submit a notice of administrative amendment to IDEM, or they may be required to submit an application for a registration modification concerning the proposed change prior to making it.
Anything on the list of exemptions under 326 IAC 2-1.1-3 is exempt, as long as the new total source PTE does not trigger the source to need a higher level permit. Exempt changes can be made with no notice to the public or IDEM. However, if the Permittee wishes IDEM to review the change and agree, the Permittee will need to submit an application.
Permittees are only required to notify IDEM of administrative amendment changes within any registered source proposing to make a change or modification that is not described under Modification Exemptions at Registered Sources or an administrative amendment change to a Registered Source must submit an application concerning the proposed change or modification prior to making the change or modification. In addition to including all relevant administrative information, a construction schedule, and information regarding the emission unit(s) and any emission control equipment comprising the source, the applicant also must identify any new applicable requirements to which the source will be subject to as a result of the changes, including emission limits and monitoring and record keeping requirements as appropriate.
To view 326 IAC 2-1.1-3 Exemptions, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
MSOP and FESOP
IDEM will issue a permit document that serves as both the construction and operating permit. Operating permits include: the Minor Source Operating Permit (MSOP), the Federally Enforceable State Operating Permit (FESOP) or the Title V Operating Permit. Details on the applicability of each are provided in the Indiana Administrative Code at 326 IAC 2-6.1-6, 326 IAC 2-8-10 and 326 IAC 2-8-11.1. To find the rules, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
Modifications at MSOP and FESOPs
MSOPs and FESOPs can be modified by an AA or administrative amendment, minor permit revision, or significant permit revision. One can review the applicability of each at 326 IAC 2-6.1-6, 326 IAC 2-8-10, and 326 IAC 2-8-11.1.
Title V Operating Permit
Title V of the 1990 Clean Air Act Amendments requires all major sources and some smaller sources of air pollution to obtain an operating permit. A Title V permit grants a source permission to operate. These permits are often called part 70 permits because the regulations that establish minimum standards for state permit programs are found in Title 40, part 70 of Code of Federal Regulations (40 CFR 70). The Title V permit includes all air pollution requirements that apply to the source, including emissions limits and monitoring, record keeping, and reporting requirements. It also requires that the source report its compliance with permit conditions to IDEM.
The U.S. EPA Laws, Regulations, Guidance and Dockets site provides additional information on Title 40 of the Code of Federal Regulations (40 CFR).
Modifications at Title V Source and to Title V Permits
Title V is the only air permit program that requires two separate approvals for a single change. The construction approval is a source modification. The operation approval is a permit modification. IDEM will process them together. Some of the permit modifications will need to go to U.S. EPA for review. Therefore, IDEM may issue the source modification first.
Title V sources can have minor and significant modifications. Title V permits can have AAs (administrative amendments), minor modifications, and significant modifications.
Regulatory details are provided in the Indiana Administrative Code at 326 IAC 2-7-10.5, 326 IAC 2-7-11, and 326 IAC 2-7-12. To find the rules, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
|Registration Thresholds Table|
(Potential to Emit Equal to, or greater than) in Tons/Year
(But less than) in Tons/Year
|(VOCs) Volatile Organic Compounds for sources not required to use air pollution control equipment to comply with the VOC emission rules||10||25|
|(VOCs) Volatile Organic Compounds for sources that are required to use air pollution control equipment to comply with the VOC emission rules||5||25|
Nitrogen dioxide and oxides of nitrogen
Particulate matter less than 10 microns
|Lead||0.2 (400 pounds)||5|
|Total Reduced Sulfur||5||25|
|Reduced Sulfur Compounds||5||25|
|Title V Thresholds for Major Sources|
|Type of Pollutant||Title V (Major Source)
potential to emit Threshold (in Tons Per Year)
|Volatile organic compounds (VOCs)
(Related to ozone formation)
25 TPY in severe nonattainment areas
|Nitrogen dioxide and oxides of nitrogen (NOX)
(Related to ozone formation)
|Sulfur dioxide||100 TPY|
|Carbon monoxide||100 TPY|
|PM-10 (Particulate matter smaller than 10 microns)||100 TPY|
|PM-2.5 (Particulate matter smaller than 2.5 microns)||100 TPY|
|A single hazardous air pollutant (HAP)||10 TPY|
|A combination of HAPs||25 TPY|
Note: Secondary Lead Smelters are required to have a Title V permit by 40 CFR 63 Subpart X.
Source Specific Operating Agreements (SSOAs)
IDEM has a Source Specific Operating Agreements (SSOAs) program under which specific types of activities may operate, provided they accept the pre-established terms of the SSOA "as is." A source may operate under more than one SSOA, up to four, or under a SSOA and some other type of operating permit as long as the total potential to emit for any regulated pollutant does not exceed major source levels.
A construction permit may not be required for facilities that seek a SSOA. Those limiting emissions below 25 tons per year would fall below the threshold requiring a new construction permit under New Source Review requirements.
The annual "actual emission" limits of SSOAs range from equal to or less than 2 tons per year for the Surface Coatings or Graphic Arts in Lake or Porter County SSOA to the equal to or less than 100 TPY limit for large Sand and Gravel or for Coal Mine or Coal Preparation SSOAs.
Except for coal mining and some stone crushing facilities, SSOAs do not have an annual fee, but must file an annual Compliance Certification. SSOAs also do not need to be renewed so long as the source complies with the operational limits in the agreement.
Source Specific Operating Agreement (SSOA) application forms need to be completed if the applicant elects to comply with the SSOA rules codified in the Indiana Administrative Code at 326 IAC 2-9. To review 326 IAC 2-9, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
Permit-by-Rule Operating Permit
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.
Permit-by-Rules under 326 IAC 2-11 do not need a construction permit. Permit-by-Rules under 326 IAC 2-11 contain specific throughput limits to limit PTE. Currently, there are Permit-by-Rules under 326 IAC 2-11 for grain elevators, grain mills, and gasoline stations.
To review 326 IAC 2-11 and regulatory details on Permit-by-Rule, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
Permit-by-Rule is an operating permit program for sources that have obtained the proper construction permit from IDEM.
Operating under the Permit-by-Rule program
Provided the appropriate construction and operating permit requirements have been met, sources whose actual emissions (not PTE) are less than 20 percent of any major permitting thresholds without the use of pollution control devices may operate under the Permit-by-Rule program. For example, the Permit-by-Rule operating program would apply to sources located within an attainment area that have actual emissions less than 20 tons per year (TPY) of carbon monoxide, oxides of nitrogen (NOX), sulfur dioxide (SO2), volatile organic compounds (VOCs), or particulate matter smaller than 10 microns (PM-10), less than 2 TPY of lead or any other single hazardous air pollutant (HAP), or 5 TPY of a combination of HAPs.
In nonattainment areas, a source must have actual emissions that are less than 20 percent of the area-specific threshold in order to participate in the Permit-by-Rule program. For example, for Lake or Porter counties, where 25 TPY is the major source threshold for VOCs, only sources with actual VOC emissions less than 5 TPY would qualify to participate.
Eligible sources wishing to operate under the Permit-by-Rule must first request that IDEM revoke their current operating permit.
A source that would no longer be eligible to participate in the Permit-by-Rule operating permit program, would need to seek coverage under the proper construction and operating permit programs.
To review 326 IAC 2-10 and 326 IAC 2-11, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
Interim Construction Permits
Interim Construction Permits allow the applicant, under limited circumstances, to commence, at their own risk, the construction or modification of a new emissions unit or control device at an existing source while the permit revision application is being reviewed. Interim approvals are subject to the requirements of 326 IAC 2-13-1. For regulatory details, visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2.
A $625 filing fee is assessed.
IDEM is allotted varying amounts of time to act on approval requests:
- Seventeen days after the publication of the public notice if no comments are submitted within the public comment period; or
- Thirty-one (31) days after the publication of the public notice if comments are submitted within the public comment period; or,
- Nineteen days after the receipt of the petition for the interim, ranging from 17 to 31 days, depending on whether comments are received and whether it is a minor or significant modification, whichever is the later date of the above.
Interim approvals are automatic if IDEM does not issue a decision. However, interim approval expires on the effective date of the final permit modification/revision approval or denial.
For details and to download application forms, visit IDEM’s Web page for Interim Approval Information.
The interim petition is applicable to proposed modification/revision to an existing source operating under valid operating permit(s) and located in an attainment area for the pollutants of concern. An emitter of VOC could not get an interim in an ozone nonattainment area. A source that emitted PM-10 and no VOC could get an interim in an ozone nonattainment area (assuming the area is attainment for PM-10).
Modifications/revisions ineligible for the interim petition program include: construction of a new major PSD facility or major PSD modification to an existing source; construction in nonattainment areas that would emit those pollutants for which the nonattainment designation is based; or, construction of a totally new plant, or any modification that is subject to 326 IAC-4.1.
Portable sources are stationary sources that can be "easily" relocated. Portable sources emit while sitting in one place and do not emit while in transit. Examples are concrete batch mixer plants or asphalt plants.
Permittees may request that their permit be a "portable" permit. This will allow the Permittee to use the same permit throughout the state. Portable sources, must obtain approval prior to relocation.
Since the permit will be valid in various locations throughout the state, the permit must contain all applicable requirements for any of the locations the Permittee wishes to move the source. Certain areas (normally the nonattainment areas) have more stringent requirements. Permittees may agree to not be allowed to move to certain areas and not have those areas' requirements in the permit. A current common example is Lake county.
One might think that "mobile" sources and "portable" sources are the same thing. This is not true (as far as Air Permitting is concerned). Mobile sources are cars, trucks, buses, etc. They are sources that emit as they move. Currently, IDEM does not issue permits to mobile sources.
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).
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. Failure to follow requirements will result in your confidential information becoming a public record and being made available for public inspection. For more information, visit IDEM’s Web page for Confidential Business Information and Trade Secrets and refer to the regulations found in the Indiana Administrative Code at 326 IAC 17.1-4-1 (visit the Web page for the Indiana Administrative Code on the Indiana General Assembly’s Web site, scroll down and click on the link for Title 326, and then click on Article 2).
Submitting your Permit Application
Always send one (1) original application packet and two (2) copies 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.
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. Refer to Part H of the GSD-01 form (now available on the IDEM Forms page) 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.
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.
For Title V Operating Permits and Federally Enforceable State Operating Permits (FESOPs), send in the application 9 months before the expiration date. For a Minor Source Operating Permit (MSOP), send in the application 120 days before the expiration date. For more information, visit IDEM’s Air Operating Permit Renewal Web page.