Indiana Air Permits

Air permits & authorizations

• Exemptions

  Exemption

  Sources below registration thresholds and listed exempt activities do not need a permit.

  326 IAC 2Official page

• Registration

  Registration / Notice

  For sources with PTE in the registration range; IDEM also offers other alternate approval programs.

  Thresholds (summarized from source, not a quotation)

  Per IDEM table (PTE, tpy, min to <max): VOC 10-25 (5-25 if VOC rules require controls); NOx 10-25; CO 25-100; SO2 10-25; PM, PM10, PM2.5 5-25; lead 0.2-5; fluorides, H2S, TRS, reduced sulfur compounds 5-25.

  326 IAC 2Official page

• Minor Source Operating Permit (MSOP)

  State Operating

  For natural minor sources with PTE between registration and Part 70 thresholds that are not otherwise subject to Part 70.

  326 IAC 2-6.1Official page

• Federally Enforceable State Operating Permit (FESOP)

  State Operating

  For sources that would be Part 70 based on PTE but agree to limit PTE below Title V thresholds.

  326 IAC 2-8Official page

• Minor NSR (construction permits)

  Minor NSR

  For sources not requiring PSD or nonattainment NSR, in attainment and nonattainment areas. New sources: 326 IAC 2-5.1-3. Modifications: 326 IAC 2-7-10.5 (Part 70), 2-6.1-6 (MSOP), 2-8-11.1 (FESOP).

  326 IAC 2-5.1-3Official page

Major NSR (PSD & nonattainment)

• Prevention of Significant Deterioration

  PSD

  New PSD major sources and major modifications in attainment/unclassifiable areas. BACT, air quality analysis, additional impacts analysis, public participation.

  326 IAC 2-2Official page

• Nonattainment NSR (Emission Offset)

  Nonattainment NSR

  New emission offset major sources and major modifications in nonattainment areas. LAER, offsets, public participation.

  326 IAC 2-3Official page

Title V operating permits

• Part 70 Operating Permit (Title V)

  Title V

  For sources with PTE above Title V major source thresholds or in categories requiring Title V.

  Thresholds (summarized from source, not a quotation)

  Per IDEM table (PTE, tpy): VOC and NOx 100 (attainment/marginal/moderate), 50 serious, 25 severe, 10 extreme; SO2, CO, PM10, PM2.5 100; lead 10; single HAP 10; combined HAPs 25; other regulated pollutants 100.

  326 IAC 2-7Official page

Oil & Gas

IDEM's air permitting pages reviewed list no oil-and-gas-specific air permit. Oil and gas facilities follow the PTE-based registration/MSOP/FESOP/Part 70 framework.

State air regulations

• 326 IAC 2Permit Review Rules
• 326 IAC 2-2Prevention of Significant Deterioration
• 326 IAC 2-3Emission Offset (nonattainment NSR)
• 326 IAC 2-5.1Construction of New Sources
• 326 IAC 2-6.1Minor Source Operating Permit Program
• 326 IAC 2-7Part 70 Permit Program
• 326 IAC 2-8Federally Enforceable State Operating Permit Program

Forms

• Application process

Guidance

• Who needs an air permit
• Emissions applicability thresholds
• Potential to emit and source category
• Operating permits
• New source review

Compliance

State compliance obligations (reporting, emissions inventory, testing) are being indexed. Use the Compliance dashboard preview to see how they will be tracked.

Sources

• IDEM Operating Permits
• IDEM Emissions Applicability Thresholds
• IDEM New Source Review

Editorial note: IDEM says its threshold tables are for reference and applicants should refer to the rules. Rule titles for 326 IAC 2 subdivisions are standard titles; confirm in the rule PDF.