Illinois Air Permits

Air permits & authorizations

• Permit exemptions

  Exemption

  Appendix 2 / Section 201.146 lists equipment and activities that need no construction or operating permit (e.g., certain small combustion units, storage tanks, cold cleaning degreasers). Exempt units must still meet other requirements and can count toward NSR or CAAPP applicability.

  35 Ill. Adm. Code 201.146Official page

• Registration of Smaller Sources (ROSS)

  Registration / Notice

  Registration replaces a permit for eligible small sources, based on prior-year actual emissions from non-exempt units. Annual fee applies.

  Thresholds (summarized from source, not a quotation)

  Per Illinois EPA guide: up to 5.0 tons/yr combined PM, CO, NOx, SO2, and VOM; 0.50 tons/yr combined HAPs; 0.05 tons/yr lead; 0.05 tons/yr mercury.

  35 Ill. Adm. Code 201.175Official page

• Construction Permit

  Minor NSR

  Required before building an emission unit or air pollution control equipment, or making a modification, unless exempt.

  35 Ill. Adm. Code 201.142-201.144Official page

• Lifetime State Operating Permit

  State Operating

  Operating permit for non-CAAPP, non-FESOP sources that does not require renewal unless the Agency requests it.

  Ill. Environmental Protection Act; 35 Ill. Adm. Code 201Official page

• General Permits

  General Permit

  Available only to true minor sources; allow adding or modifying units within the permit's limits without a new construction permit. Illinois EPA has also issued general FESOPs (e.g., batch-mix asphalt).

  Ill. Environmental Protection Act § 39.10Official page

• Federally Enforceable State Operating Permit (FESOP)

  State Operating

  Voluntary synthetic minor permit with federally enforceable limits keeping potential emissions below major source thresholds.

  Official page

Major NSR (PSD & nonattainment)

• PSD

  PSD

  Major source review in attainment areas.

  Thresholds (summarized from source, not a quotation)

  Per Illinois EPA guide: 100 tons/yr for 28 listed source categories; 250 tons/yr for others.

  40 CFR 52.21Official page

• Nonattainment New Source Review

  Nonattainment NSR

  Major source review in nonattainment areas.

  Thresholds (summarized from source, not a quotation)

  Per Illinois EPA guide: 100 tons/yr in a nonattainment area (lower thresholds may apply depending on classification).

  35 Ill. Adm. Code Part 203Official page

Title V operating permits

• Clean Air Act Permit Program (CAAPP)

  Title V

  Illinois's Title V program for major sources and certain other sources.

  Thresholds (summarized from source, not a quotation)

  Per Illinois EPA guide: 100 tons/yr of any criteria pollutant; 10 tons/yr of any single HAP; 25 tons/yr of combined HAPs (potential to emit at 8,760 hours/yr).

  Ill. Environmental Protection Act § 39.5Official page

Oil & Gas

Illinois EPA's permitting pages list no oil-and-gas-specific air permit. Oil and gas facilities follow construction, lifetime, FESOP, or CAAPP permitting; federal NSPS OOOO-series and NESHAP HH apply where applicable.

State air regulations

• 35 Ill. Adm. Code Part 201Permits and General Provisions (201.102 definitions; 201.142-144 permits; 201.146 exemptions; 201.175 ROSS)
• 35 Ill. Adm. Code Part 203Major Stationary Sources Construction and Modification (nonattainment NSR)
• 415 ILCS 5/39.5Clean Air Act Permit Program (CAAPP)
• 415 ILCS 5/39.10General permits

Forms

• State (non-CAAPP) permit forms
• Lifetime permit and ROSS forms
• FESOP forms
• CAAPP forms

Guidance

• Does My Business Need an Air Pollution Control Permit?
• Determining Potential to Emit
• Annual Emission Reports
• Aggregate Processing Plant Application Guidance

Compliance

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

Sources

• Illinois EPA Air Permits
• Illinois EPA permit eligibility guide (2016)
• Cook County Equipment Registration Permitting

Editorial note: The Illinois EPA eligibility guide is dated 2016; fee amounts and ROSS deadlines in it may be outdated. The Chicago-area ozone nonattainment classification can lower major source thresholds; check the Green Book.