Section 203.100  Effective Dates

 

a)         Subparts I through R of this Part do not apply until the effective date of the full approval of all of those Subparts by the United States Environmental Protection Agency (USEPA) as a revision to the Illinois State Implementation Plan.

 

b)         On the effective date of the full approval of Subparts I through R of this Part by the USEPA as part of Illinois' State Implementation Plan, the permitting and operation of projects that began actual construction or may begin actual construction before this date shall continue to be in compliance with Subparts A through H of this Part.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.101  Definitions

 

Unless otherwise specified within this Part, the definitions of terms used in this Part shall be the same as those used in the Pollution Control Board (Board) Rules and Regulations 35 Ill. Adm. Code 201 and 211.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.103  Actual Construction

 

"Actual Construction" means in general, initiation of physical on-site construction activities on an emissions unit which are of a permanent nature.  Such activities include, but are not limited to, installation of building supports and foundations, laying of underground pipework, and erection of permanent storage structures.  With respect to a change in method of operation, this term refers to those on-site activities other than preparatory activities which mark the initiation of the change.

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.104  Actual Emissions

 

"Actual Emissions" means the actual rate of annual emissions of a pollutant from an emissions unit as of a particular date.  Actual emissions are equal to the average rate, in tons per year, at which the emissions unit actually emitted the pollutant during the two-year period which immediately precedes the particular date or such other period which is determined by the Illinois Environmental Protection Agency (Agency) to be representative of normal source operation.  Actual emissions shall be calculated using the unit's actual operating hours, production rates, and types of materials processed, stored or combusted during the selected time period; however:

 

a)         The Agency shall allow the use of a different time period upon a demonstration by the applicant to the Agency that the time period is more representative of normal source operation.  Such demonstration may include, but need not be limited to, operating records or other documentation of events or circumstances indicating that the preceding two years is not representative of normal source operations.

 

b)         The Agency may presume in the absence of reliable data on actual emissions that the source-specific allowable emissions for the emissions unit are equivalent to the actual emissions of the emissions unit.

 

c)         For any emissions unit which has not begun normal operations on the particular date, the Agency shall presume that the potential to emit of the emissions unit is equivalent to the actual emissions on that date.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.107  Allowable Emissions

 

a)         "Allowable emissions" means the emission rate of a stationary source calculated using the maximum rated capacity of the source (unless the source is subject to federally enforceable permit conditions or other such federally enforceable limits which restrict the operating rate, or hours of operation, or both) and the most stringent of the following:

 

1)         Any applicable standards adopted by the United States Environmental Protection Agency (USEPA) pursuant to Sections 111 and 112 of the Clean Air Act (42 U.S.C. 7401, et seq.) and made applicable in Illinois pursuant to Section 9.1 of the Environmental Protection Act (Act) (Ill. Rev. Stat. 1991, ch. 111½, pars. 1001 et seq.) [415 ILCS 5/1 et seq.];

 

2)         The applicable emission standards or limitations contained in this Chapter and approved by USEPA pursuant to Section 110(a)(2) or 110 (a)(3) of the Clean Air Act, including those standards or limitations with a future compliance date and any other emission standard or limitation enforceable under the Environmental Protection Act or by the USEPA under Section 113 of the Clean Air Act; or

 

3)         The emissions rate specified as a federally enforceable permit condition including those emissions rates with a future compliance date.

 

b)         The allowable emissions may be based on a federally enforceable permit condition limiting material or fuel throughput.

 

c)         If a source is not subject to an emission standard described in subsection (a) above and is not subject to a permit condition described in subsection (b), the allowable emissions shall be the source's potential to emit.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.110  Available Growth Margin

 

"Available growth margin" means the portion which remains of any emission allowance for new or modified major stationary sources expressly identified in the attainment demonstration approved by the United States Environmental Protection Agency under Section 172(c)(4) of the Clean Air Act (42 U.S.C. 7502(c)(4)) for a particular pollutant and area in a zone (within a nonattainment area) to which economic development should be targeted, in accordance with Section 173(a)(1)(B) of the Clean Air Act (42 U.S.C. 7503(a)(1)(B)).

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.112  Building, Structure and Facility

 

a)         The terms "building", "structure", and "facility" include all of the pollutant-emitting activities which belong to the same industrial grouping, are located on one or more contiguous or adjacent properties, and are under the control of the same person (or persons under common control). Pollutant-emitting activities shall be considered as part of the same "Major Group" (i.e., which have the same two-digit code) as described in the Standard Industrial Classification Manual, 1972, as amended by the 1977 Supplement (U.S. Government Printing Office stock numbers 4101-0066 and 003-005-00176-0, respectively) incorporated by reference in 35 Ill. Adm. Code 720.111.

 

b)         The terms "building", "structure", and "facility" shall also include

 

1)         the transfer of materials, including but not limited to grain, gasoline, petroleum liquids, coal, fertilizer, crushed stone and ore, from vessels, motor vehicles or other conveyances, irrespective of ownership or industrial grouping, to or from a building, structure, or facility as defined in subsection (a) above, and

 

2)         activities at or adjacent to such building, structure or facility which are associated with such transfer, including but not limited to the operating of engines to provide heat, refrigeration or lighting, operation of auxiliary engines for pumps or cranes, and transfer of materials from hold to hold or tank to tank during onloading or offloading operations except those activities causing emissions resulting directly from internal combustion engines from transportation purposes or from a non road engine or non road vehicle as defined in Section 216 of the Clean Air Act (42 U.S.C. 7401 et seq.).

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.113  Commence

 

As applied to construction of a major stationary source or major modification "commence" means that the owner or operator has obtained all necessary preconstruction approvals or permits and either has:

 

a)         Begun, or caused to begin, a continuous program of actual on-site construction of the source, to be completed within a reasonable time; or

 

b)         Entered into binding agreements or contractural obligations, which cannot be cancelled or modified without substantial loss to the owner or operator, to undertake a program of actual construction of the source to be completed within a reasonable time.

 

c)         For purposes of this Secton, a "reasonable time" shall be determined considering but not limited to the following factors:  The nature and size of the project, the extent of design engineering, the amount of off-site preparation, whether equipment can be fabricated or can be purchased, when the project begins (considering both the seasonal nature of construction activity and the existence of other projects competing for construction labor at the same time, the place of the environmental permit in the sequence of corporate and overall governmental approval), and the nature of the permittee (private, public, regulated, etc).

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 28, 1988)

 

Section 203.116  Construction

 

"Construction" means any physical change or change in the method of operation, including but not limited to fabrication, erection, installation, demolition, or modification of an emissions source unit, which would result in a change in actual emissions.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.117  Dispersion Enhancement Techniques

 

"Dispersion Enhancement Techniques" mean so much of the stack height of any source as exceeds good engineering practice or any other dispersion technique, determined by regulations at 40 CFR 51.100 (1987) (no future amendments or editions are included).

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.119  Emission Baseline

 

"Emission baseline" means the starting point or reference level from which increases and decreases in emissions are measured.  The rules governing determination of emission offsets, calculations of net emission increases, and evaluation under 35 Ill. Adm. Code 202, Alternative Control Strategies specify the particular emission baseline that applies for that purpose.

 

Section 203.121  Emission Offset

 

"Emission offset" means a creditable emission reduction used to compensate for the increase in emissions resulting from a new major source or a major modification in accordance with Sections 203.302 and 203.303 of this Part.

 

(Source:  Section 203.121 renumbered from Section 203.122 and amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.122  Emissions Unit

 

"Emissions unit" means any part of a stationary source which emits or has the potential to emit any air pollutant subject to regulation under the Act or this Chapter or by the United States Environmental Protection Agency under the Clean Air Act (42 U.S.C. 7401 et seq.).

 

(Source:  Former Section 203.122 renumbered to Section 203.121, Section 203.122 renumbered from Section 203.123, and Section amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.123  Federally Enforceable

 

"Federally enforceable" means enforceable by the United States Environmental Protection Agency.

 

(Source:  Former Section 203.123 renumbered to Section 203.122, new Section 203.123 added at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.124  Fugitive Emissions

 

"Fugitive Emissions" means those emissions which could not reasonably pass through a stack, chimney, vent or other functionally equivalent opening.

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.125  Installation

 

"Installation" means an identifiable piece of equipment, including, but not limited to, boilers, furnaces, reactors, dryers, incinerators, heaters, and coating lines.

 

(Source:  Former Section 203.125 renumbered to Section 203.126, new Section 203.125 adopted at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.126  Lowest Achievable Emission Rate

 

"LAER" is an acronym for lowest achievable emission rate.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.127  Nonattainment Area

 

An area designated by USEPA as nonattainment for a given pollutant pursuant to Section 107 of the Clean Air Act (42 U.S.C. 7407).

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.128  Potential to Emit

 

"Potential to emit" means the maximum capacity of a stationary source to emit a pollutant under its physical and operational design.  Any physical or operational limitation on the capacity of the source to emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design only if the limitation or the effect it would have on emissions is federally enforceable.  Secondary emissions do not count in determining the potential to emit of a stationary source.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.131  Reasonable Further Progress

 

"Reasonable Further Progress" means the annual incremental reductions in the emissions of the applicable air pollutant as determined by USEPA pursuant to Part D of the Clean Air Act (42 U.S.C. 7501 et seq.) and federal regulations adopted pursuant thereto.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.134  Secondary Emissions

 

"Secondary Emissions" means the emissions which would occur as a result of the construction or operation of a major stationary source or major modification, but do not come from the major stationary source or major modification itself.  For the purpose of this Part, secondary emissions must be specific, well defined, quantifiable, and impact the same general area as the stationary source or modification which causes the secondary emissions.  Secondary emissions may include, but are not limited to, emissions from any off-site support facility which would not otherwise be constructed or increase its emissions except as a result of the construction or operation of the major stationary source or major modification.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.136  Stationary Source

 

"Stationary Source" means any building, structure, facility or installation which emits or may emit any air pollutant subject to regulation under the Act or this Chapter or by USEPA under the Clean Air Act (42 U.S.C. 7401 et seq.).

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.145  Volatile Organic Material (Repealed)

 

(Source:  Repealed at 17 Ill. Reg. 16630, effective September 27, 1993)

 

Section 203.150  Public Participation

 

Prior to the initial issuance or revision of a permit pursuant to Subpart B, the Agency shall provide, at a minimum, notice of the proposed issuance of a permit, a comment period, and opportunity for public hearing pursuant to the Agency public participation procedures set forth at 35 Ill. Adm. Code 252.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.155  Severability (Repealed)

 

(Source:  Repealed at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.201  Prohibition

 

In any nonattainment area, no person shall cause or allow the construction of a new major stationary source or major modification that is major for the pollutant for which the area is designated a nonattainment area, except as in compliance with this Part for that pollutant. In areas designated nonattainment for ozone, this prohibition shall apply to new major stationary sources or major modifications of sources that emit volatile organic materials or nitrogen oxides. Revisions to this Part which were adopted to implement the Clean Air Act Amendments of 1990 shall not apply to any new major stationary source or major modification for which a permit application was submitted by June 30, 1992 for PM-10, May 15, 1992 for SO₂, or by November 15, 1992 for nitrogen oxides and volatile organic material emissions for sources located in all ozone nonattainment areas.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.202  Coordination with Permit Requirement and Application Pursuant to 35 Ill. Adm. Code 201

 

For new major sources and major modifications, the fulfillment of the requirements of 35 Ill. Adm. Code 201 related to construction, including the permit requirements of 35 Ill. Adm. Code 201.142, shall be combined with the requirements of this Subpart.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.203  Construction Permit Requirement and Application

 

a)         A construction permit is required prior to actual construction of a major new source or major modification.

 

b)         Applications for construction permits required under this Section shall contain sufficient information to demonstrate compliance with 35 Ill. Adm. Code 201 and the requirements of this Part including, but not limited to, Subpart C.

 

c)         The permit shall include conditions specifying the manner in which the requirements of Subparts B and C of this Part are satisfied.

 

d)         No permittee shall violate any condition contained in a construction permit issued for a new major stationary source or major modification which is subject to this Part.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.204  Duration of Construction Permit (Repealed)

 

(Source:  Repealed at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.205  Effect of Permits

 

The issuance of a permit for a source subject to the requirements of this Part shall not relieve any person of the responsibility to comply fully with applicable provisions of the Environmental Protection Act (Act) (Ill. Rev. Stat. 1985, ch. 111 1/2, pars 1001 et seq.), and any other applicable requirements under local, state or federal law.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.206  Major Stationary Source

 

a)         For purposes of this Part, the term "major stationary source" shall exclusively mean "building, structure and facility," as those terms are defined in Section 203.113 of this Part.

 

b)         The following constitute a major stationary source:

 

1)         For an area designated as nonattainment for ozone, a major stationary source is a stationary source which emits or has the potential to emit volatile organic material in an amount equal to or greater than the following:

 

A)        100 tons per year in an area classified as marginal or moderate nonattainment for ozone;

 

B)        50 tons per year in an area classified as serious nonattainment for ozone;

 

C)        25 tons per year in an area classified as severe nonattainment for ozone; and

 

D)        10 tons per year in an area classified as extreme nonattainment for ozone.

 

2)         For an area designated as nonattainment for nitrogen dioxide, a major stationary source is a stationary source which emits or has the potential to emit 100 tons per year or more of nitrogen dioxide.

 

3)         For an area designated as nonattainment for ozone, a major stationary source is a stationary source which emits or has the potential to emit nitrogen oxides in an amount equal to or greater than the following, unless United States Environmental Protection Agency (USEPA) has made a finding under Sections 110 and 182(f) of the Clean Air Act that controlling of emissions of nitrogen oxides from such source shall not be required:

 

A)        100 tons per year in an area classified as marginal or moderate nonattainment for ozone,

 

B)        50 tons per year in an area classified as serious nonattainment for ozone,

 

C)        25 tons per year in an area classified as severe nonattainment for ozone, and

 

D)        10 tons per year in an area classified as extreme nonattainment for ozone.

 

4)         For an area designated nonattainment for PM-10, a major stationary source is a stationary source which emits or has the potential to emit:

 

A)        100 tons per year or more of PM-10 in an area classified as moderate nonattainment area, or

 

B)        70 tons per year or more of PM-10 in an area classified as serious nonattainment.

 

5)         For an area designated nonattainment for carbon monoxide, a major stationary source is a stationary source which emits or has the potential to emit:

 

A)        100 tons per year or more of carbon monoxide in a nonattainment area, except as provided in subsection (b)(5)(B),

 

B)        50 tons per year or more in an area classified as "serious" nonattainment for carbon monoxide where stationary sources significantly contribute to ambient carbon monoxide levels, as determined under rules issued by USEPA, pursuant to the Clean Air Act.

 

6)         For an area designated nonattainment for a pollutant other than ozone, nitrogen dioxide, PM-10 or carbon monoxide, a major stationary source is a stationary source which emits or has the potential to emit 100 tons per year or more of the pollutant.

 

c)         Any physical change that occurs at a stationary source which does not qualify under subsection (a) of this Section as a major stationary source will be considered a major stationary source, if the change would constitute a major stationary source by itself.

 

d)         For purposes of this Part, in areas that are classified as serious, severe, or extreme nonattainment, the fugitive emissions of a stationary source shall be included in determining whether it is a major stationary source.  In areas that are not classified as serious, severe or extreme nonattainment, the fugitive emissions of a stationary source shall not be included in determining whether it is a major stationary source, unless the source belongs to one of the following categories of stationary sources:

 

1)         Coal cleaning plants (with thermal dryers);

 

2)         Kraft pulp mills;

 

3)         Portland cement plants;

 

4)         Primary zinc smelters;

 

5)         Iron and steel mills;

 

6)         Primary aluminum ore reduction plants;

 

7)         Primary copper smelters;

 

8)         Municipal incinerators capable of charging more than 250 tons of refuse per day;

 

9)         Hydrofluoric, sulfuric, or nitric acid plants;

 

10)         Petroleum refineries;

 

11)         Lime plants;

 

12)         Phosphate rock processing plants;

 

13)         Coke oven batteries;

 

14)         Sulfer recovery plants;

 

15)         Carbon black plants (furnace process);

 

16)         Primary lead smelters;

 

17)         Fuel conversion plants;

 

18)         Sintering plants;

 

19)         Secondary metal production plants;

 

20)         Chemical process plants;

 

21)         Fossil-fuel boilers (or combination thereof) totaling more than 250 million Btu per hour heat input;

 

22)         Petroleum storage and transfer units with a total storage capacity exceeding 300,000 barrels;

 

23)         Taconite ore processing plants;

 

24)         Glass fiber processing plants;

 

25)         Charcoal production plants;

 

26)         Fossil fuel-fired steam electric plants of more than 250 million Btu per hour heat input;

 

27)         Any other stationary source categories regulated by a standard promulgated under Section 111 or 112 of the Clean Air Act (42 U.S.C. 7411, 7412), but only with respect to those air pollutants that have been regulated for that category;

 

28)         Any other stationary source category designated by the USEPA by rule.

 

(Source:  Amended at 22 Ill. Reg. 5674, effective March 10, 1998)

 

Section 203.207  Major Modification of a Source

 

a)         Except as provided in subsection (c), (d), (e) or (f), a physical change, or change in the method of operation of a major stationary source that would result in a significant net emissions increase of any pollutant for which the area is designated a nonattainment area, shall constitute a major modification of a source.

 

b)         Any net emissions increase that is significant for volatile organic material or nitrogen oxides shall be considered significant for ozone.

 

c)         A physical change or change in the method of operation shall not include:

 

1)         Routine maintenance and repair.

 

2)         Use of an alternative fuel or raw material by reason of any order under Section 2(a) and (b) of the Energy Supply and Environmental Coordination Act of 1974 (15 USC 791), the Power Plant and Industrial Fuel Use Act of 1978 (42 USC 8301) (or any superseding legislation) or by reason of a natural gas curtailment plan under the Federal Power Act (16 USC 791, et seq.).

 

3)         Use of an alternative fuel by reason of an order or rule under Section 125 of the Clean Air Act (42 USC 7425).

 

4)         Use of an alternative fuel at a steam generating unit to the extent that the fuel is generated from municipal solid waste.

 

5)         Use of an alternative fuel or raw material by a stationary source that:

 

A)        Was capable of accommodating such alternative fuel or raw material before December 21, 1976, and that has continuously remained capable of accommodating such fuels or materials unless such change would be prohibited under any enforceable permit condition established after December 21, 1976, under 40 CFR 52.21, 35 Ill. Adm. Code 204, this Part, or 35 Ill. Adm. Code 201.142 or 201.143; or

 

B)        Is approved for use under any permit issued under this Part or 35 Ill. Adm. Code 201.142 or 201.143.

 

6)         An increase in the hours of operation or in the production rate, unless such change is prohibited under any enforceable permit condition that was established after December 21, 1976 under 40 CFR 52.21, 35 Ill. Adm. Code 204, this Part, or 35 Ill. Adm. Code 201.142 or 201.143.

 

7)         Any change in ownership at a stationary source.

 

d)         In an area classified as serious or severe nonattainment for ozone, increased emissions of volatile organic material or nitrogen oxides resulting from any physical change in, or change in the method  of operation of, a stationary source located in the area shall be considered de minimis for purposes of this Part if the increase in net emissions of such air pollutant from such source does not exceed 25 tons when aggregated with all other net increases in emissions from the source over any period of five consecutive calendar years that includes the year in which such increase occurred.

 

e)         In the case of any major stationary source of volatile organic material or nitrogen oxides located in an area classified as serious or severe nonattainment for ozone (other than a source that emits or has the potential to emit 100 tons or more of volatile organic material or nitrogen oxides per year), whenever any change at that source results in any increase (other than a de minimis increase) in emissions of volatile organic material or nitrogen oxides, respectively, from any discrete operation, unit, or other pollutant emitting activity at the source, such increase shall be considered a major modification for purposes of this Part, except such increase shall not be considered a major modification for such purposes if the owner or operator of the source elects to offset the increase by a greater reduction in emissions of volatile organic material or nitrogen oxides, respectively, from other operations, units, or activities within the source at an internal offset ratio of at least 1.3 to 1.

 

f)         In areas classified as extreme nonattainment for ozone, beginning on the date that an area is classified by USEPA as an extreme nonattainment area for ozone, any physical change in or change in the method of operation of a major stationary source that results in any increase in emissions of volatile organic material or nitrogen oxides from a discrete operation, unit, or other pollutant emitting activity shall be considered a major modification.

 

(Source:  Amended at 44 Ill. Reg. 14916, effective September 4, 2020)

 

Section 203.208  Net Emission Determination

 

A net emissions increase is the amount by which the sum of any increase in actual emissions from a particular physical change or change in method of operation at a source, and any other increases and decreases in actual emissions at the source that are contemporaneous with the particular change and are otherwise creditable, exceeds zero.  The following steps determine whether the increase or decrease in emissions is available.

 

a)         Except for increases or decreases in volatile organic material and nitrogen oxide emissions in serious and severe ozone nonattainment areas which are addressed in Section 203.209(b), an increase or decrease in actual emissions is contemporaneous only if it occurs between the date that an increase from a particular change occurs and the date five years before a timely and complete application is submitted for the particular change.  It must also occur after either April 24, 1979, or the date the area is designated by the United States Environmental Protection Agency as a nonattainment area for the pollutant, whichever is more recent.

 

b)         An increase or decrease in actual emissions is creditable:

 

1)         Only if there is not in effect for the source at the time the particular change occurs a permit which relied on the same increase or decrease in actual emissions; and

 

2)         Only to the extent the new and old levels differ.

 

c)         A decrease in actual emissions is creditable to the extent that:

 

1)         It is federally enforceable at and after the time that actual construction on the particular change begins;

 

2)         It has approximately the same qualitative significance for public health and welfare as that attributed to the increase from the particular change;

 

3)         The old level of actual emissions or the old level of allowable emissions, whichever is lower, exceeds the new level of actual emissions; and

 

4)         It is demonstrated by the Agency not to have been previously relied on in issuing any permit pursuant to this Part or 35 Ill. Adm. Code 201.142 or 201.143 or for demonstrating attainment or reasonable further progress in the nonattainment area which the particular change will impact.

 

d)         An increase that results from a physical change at a source occurs when the emissions unit on which construction occurred becomes operational and begins to emit a particular pollutant.  Any replacement unit that requires shakedown becomes operational only after a shakedown period not to exceed 180 days.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.209  Significant Emissions Determination

 

a)         A net emission increase in the pollutant emitted is significant if the rate of emission is equal to or in excess of the following:

 

1)         Carbon monoxide:  100 tons per year (tpy)

 

2)         Nitrogen oxides:  40 tpy for a nonattainment area for nitrogen dioxide and 40 tpy for an ozone nonattainment area, except as provided in subsection (b) of this Section

 

3)         Sulfur dioxide:  40 tpy

 

4)         Particulate matter measured as PM-10:  15 tpy

 

5)         Ozone:  40 tpy of volatile organic material, except as provided in subsection (b) of this Section

 

6)         Lead:  0.6 tpy

 

b)         For areas classified as serious or severe nonattainment for ozone, an increase in emissions of volatile organic material or nitrogen oxides shall be considered significant if the net emissions increase of such air pollutant from a stationary source located within such area exceeds 25 tons when aggregated with all other net increases in emissions from the source over any period of 5 consecutive calendar years which includes the calendar year in which such increase occurred.  This provision shall become effective beginning November 15, 1992, or such later date that an area is classified as a serious or severe nonattainment area for ozone.

 

(Source:  Amended at 18 Ill. Reg. 6335, effective April 15, 1994)

 

Section 203.210  Relaxation of a Source-Specific Limitation

 

a)         No person shall cause or allow the operation of a source so as to exceed any enforceable limitation which affects or defines the applicability of the requirements of this Part to a stationary source or modification by specifying the permissible emission rate, operating hours, the type or amount of material processed, stored or combusted, or other aspects of source operation.

 

b)         At such time that a particular source or modification becomes a major stationary source or major modification solely by virtue of a relaxation in, or expiration of, any enforceable limitation which was established after August 7, 1980, on the capacity of the source or modification otherwise to emit a pollutant, such as a restriction on hours of operation, then the requirements of this Part shall apply as though construction had not yet commenced on the source or modification.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.211  Permit Exemption Based on Fugitive Emissions

 

The provisions of this Part shall not apply to a source or modification that would be a major stationary source or major modification only if fugitive emissions, to the extent quantifiable as evidenced by 35 Ill. Adm. Code 201.122, are considered in calculating the potential to emit of the stationary source or modification and the source does not belong to any of the categories enumerated in Section 203.206(d).

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.301  Lowest Achievable Emission Rate

 

a)         For any source, lowest achievable emission rate (LAER) will be the more stringent rate of emissions based on the following:

 

1)         The most stringent emission limitation which is contained in the implementation plan of any state for such class or category of stationary source, unless it is demonstrated that such limitation is not achievable; or

 

2)         The most stringent emission limitation which is achieved in practice by such a class or category of stationary source.  This limitation, when applied to a modification, means the lowest achievable emissions rate for the new or modified emissions units within the stationary source.  In no event shall the application of this term permit a proposed new or modified stationary source to emit any pollutant in excess of the amount allowable under an applicable new source performance standard adopted by United States Environmental Protection Agency (USEPA) pursuant to Section 111 of the Clean Air Act and made applicable in Illinois pursuant to Section 9.1 of the Act.

 

b)         The owner or operator of a new major stationary source shall demonstrate that the control equipment and process measures applied to the source will produce LAER.

 

c)         Except as provided in subsection (e) or (f) below, the owner or operator of a major modification shall demonstrate that the control equipment and process measures applied to the major modification will produce LAER.  This requirement applies to each emissions unit at which a net increase in emissions of the pollutant has occurred or would occur as a result of a physical change or change in the method of operation.

 

d)         The owner or operator shall provide a detailed showing that the proposed emission limitations constitute LAER.  Such demonstration shall include:

 

1)         A description of the manner in which the proposed emission limitation was selected, including a detailed listing of information resources,

 

2)         Alternative emission limitations, and

 

3)         Such other reasonable information as the Agency may request as necessary to determine whether the proposed emission limitation is LAER.

 

e)         If the owner or operator of a major stationary source (other than a source which emits or has the potential to emit 100 tons per year or more of volatile organic material or nitrogen oxides) located in an area classified as serious or severe nonattainment for ozone does not elect to provide internal offsets for a change at the source in accordance with Section 203.207(e) of this Part, such change shall be considered a major modification for purposes of this Part, but in applying this Section in the case of any such modification, the Best Available Control Technology (BACT), as defined in section 169 of the Clean Air Act, shall be substituted for the Lowest Achievable Emission Rate (LAER).  BACT shall be determined in accordance with policies and procedures published by USEPA.

 

f)         In the case of any major stationary source of volatile organic material or nitrogen oxides located in an area classified as serious or severe nonattainment for ozone which emits or has the potential to emit 100 tons per year or more of volatile organic material or nitrogen oxides, respectively, whenever any change at that source results in any increase (other than a de minimis increase) in emissions of volatile organic material or nitrogen oxides, respectively, from any discrete operation, unit, or other pollutant emitting activity at the source, such increase shall be considered a major modification for purposes of this Part, except that if the owner or operator elects to offset the increase by a greater reduction in emissions of volatile organic material or nitrogen oxides, respectively, from other operations, units or activities within the source at an internal offset ratio of at least 1.3 to 1, the requirements of this Section concerning LAER shall not apply.

 

(Source:  Amended at 22 Ill. Reg. 5674, effective March 10, 1998)

 

Section 203.302  Maintenance of Reasonable Further Progress and Emission Offsets

 

a)         The owner or operator of a new major source or major modification shall provide emission offsets equal to or greater than the allowable emissions from the source or the net increase in emissions from the modification sufficient to allow the Agency to determine that the source or modification will not interfere with reasonable further progress as set forth in Section 173 of the Clean Air Act (42 U.S.C. 7401 et seq.).

 

1)         For new major sources or major modifications in ozone nonattainment areas the ratio of total emission reductions provided by emission offsets for volatile organic material or nitrogen oxides to total increased emissions of such contaminants shall be at least as follows:

 

A)        1.1 to 1 in areas classified as marginal;

 

B)        1.15 to 1 in areas classified as moderate;

 

C)        1.2 to 1 in areas classified as serious;

 

D)        1.3 to 1 in areas classified as severe; and

 

E)        1.5 to 1 in areas classified as extreme.

 

2)         The offset requirement provided in subsection (1) above shall not be applicable in extreme areas to a modification of an existing source:

 

A)        if such modification consists of installation of equipment required to comply with the implementation plan or the Clean Air Act; or

 

B)        if the owner or operator of the source elects to offset the increase by a greater reduction in emissions of such pollutant from other discrete operations, units, or activities within the source at an internal offset ratio of at least 1.3 to 1.

 

b)         The Agency shall allow the use of all or some portion of the available growth margin to satisfy subsection (a) above if the owner or operator can present evidence that the possible sources of emission offsets were investigated, none were available at that time and the new or modified major stationary source is located in a zone (within the nonattainment area) identified by United States Environmental Protection Agency, in consultation with the Secretary of Housing and Urban Development, as a zone to which economic development should be targeted.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.303  Baseline and Emission Offsets Determination

 

a)         An emission offset must be obtained from a source in operation prior to the permit application for the new or modified source.  Emission offsets must be effective prior to start-up of the new or modified source.

 

b)         The emission offsets provided:

 

1)         Must be of the same pollutant and further be of a type with approximately the same qualitative significance for public health and welfare as that attributed to the increase from a particular change;

 

2)         Must, in the case of a fuel combustion source, be based on the type of fuel being burned at the time the permit application is filed, and, if offset is to be produced by a future switch to a cleaner fuel, be accompanied by evidence that long-term supplies of the clean fuel are available and a commitment to a specified alternative control measure which would achieve the same degree of emission reduction of the dirtier fuel is proposed;

 

3)         Must, in the case of a past shutdown of a source or permanent curtailment of production or operating hours, have occurred since April 24, 1979, or the date the area is designated a nonattainment area for the pollutant, whichever is more recent, and, until the United States Environmental Protection Agency (USEPA) has approved the attainment demonstration and state trading or marketing rules for the relevant pollutant, the proposed new or modified source must be a replacement for the shutdown or curtailment;

 

4)         Must be federally enforceable by permit; and

 

5)         Must not have been previously relied on, as demonstrated by the Agency, in issuing any permit pursuant to 35 Ill. Adm. Code 201.142 or 201.143 or this Part, or for demonstrating attainment or reasonable further progress.

 

c)         The baseline for determining the extent to which emission reductions are creditable as offsets shall be the actual emissions of the source from which the offset is to be obtained, to the extent they are within any applicable emissions limitations of this Chapter or the Act or any applicable standards adopted by USEPA pursuant to Section 111 and 112 of the Clean Air Act, and made applicable in Illinois pursuant to Section 9.1 of the Environmental Protection Act (Ill. Rev. Stat. 1991, ch. 111½, par. 1009.1) [415 ILCS 5/9.1].

 

d)         The location of sources providing the emission  reductions to fulfill the offset requirements of this Section:

 

1)         Must be achieved in the same nonattainment area as the increase being offset, except as provided as follows:

 

A)        An owner or operator may obtain the necessary emission reductions from another nonattainment area where such other area has an equal or higher nonattainment classification than the area in which the source is located, and

 

B)        The emission reductions from such other area contribute to a violation of the national ambient air quality standard in the nonattainment area in which the new or modified source is located.

 

2)         Must, for particulate matter, sulfur dioxide and carbon monoxide, be such that, relative to the site of the proposed new or modified source, the location of the offset, together with its effective stack height, ensures a positive net air quality benefit.  This shall be demonstrated by atmospheric simulation modeling, unless the sources providing the offset are on the same premises or in the immediate vicinity of the new or modified source and the pollutants disperse from substantially the same effective stack height. In determining effective stack height, credit shall not be given for dispersion enhancement techniques.  The owner or operator of a proposed new or modified source shall perform the analysis to demonstrate the acceptability of the location of an offset, if the Agency declines to make such analysis.  Effective stack height means actual stack height plus plume rise.  Where actual stack height exceeds good engineering practices, as determined pursuant to 40 CFR 51.100 (1987) (no future amendments or editions are included), the creditable stack height shall be used.

 

e)         Replacement of one volatile organic material with another of lesser reactivity does not constitute an emission reduction.

 

f)         Emission reductions otherwise required by the Clean Air Act (42 U.S.C. 7401 et seq.) shall not be creditable for purposes of any such offset requirement.  Incidental emission reductions which are not otherwise required by the Clean Air Act shall be creditable as emission reductions for such purposes if such emissions reductions meet the requirements of this Subpart.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.304  Exemptions from Emissions Offset Requirement (Repealed)

 

(Source:  Repealed at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.305  Compliance by Existing Sources

 

The owner or operator shall demonstrate that all major stationary sources which he or she owns or operates (or which are owned or operated by any entity controlling or controlled by, or under common control, with the owner or operator) in Illinois are in compliance, or on a schedule for compliance, with all applicable state and federal air pollution control requirements.  For purposes of this Section, a schedule for compliance must be federally enforceable or contained in an order of the Illinois Pollution Control Board or a court decree.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.306  Analysis of Alternatives

 

The owner or operator shall demonstrate that benefits of the new major source or major modification significantly outweigh the environmental and social costs imposed as a result of its location, construction, or modification, based upon an analysis of alternative sites, sizes, production processes, and environmental control techniques for such proposed source.

 

(Source:  Amended at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.601  Lowest Achievable Emission Rate Compliance Requirement

 

No person shall cause or allow the operation of a new major stationary source or major modification subject to the requirements of Subpart C, except as in compliance with applicable LAER provisions established pursuant to Section 203.301 for such source or modification.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.602  Emission Offset Maintenance Requirement

 

No person shall cause or allow the operation of a new major stationary source or major modification where the owner or operator has demonstrated that it would not interfere with reasonable further progress by providing emission offsets pursuant to Section 203.302 without maintaining those emission offsets or other equivalent offsets.

 

(Source:  Amended at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.603  Ambient Monitoring Requirement (Repealed)

 

(Source:  Repealed at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.701  General Maintenance of Emission Offsets

 

No person shall cease to maintain emission offsets which were provided for a source or modification which is subject to this Part.

 

(Source:  Added at 12 Ill. Reg. 6118, effective March 22, 1988)

 

Section 203.801  Offsetting by Alternative or Innovative Means

 

A source may offset, by alternative or innovative means, emission increases from rocket engine and motor firing, and cleaning related to such firing, at an existing or modified major source that tests rocket engines or motors under the following conditions:

 

a)         Any modification proposed is solely for the purpose of expanding the testing of rocket engines or motors at an existing source that is permitted to test such engines on November 15, 1990;

 

b)         The source demonstrates to the satisfaction of the Agency that it has used all reasonable means to obtain and utilize offsets, as determined on an annual basis, for the emissions increases beyond allowable levels, that all available offsets are being used, and that sufficient offsets are not available to the source;

 

c)         The source has obtained a written finding from  the Department of Defense, Department of Transportation, National Aeronautics and Space Administration or other appropriate Federal agency, that the testing of rocket motors or engines at the facility is required for a program essential to the national security; and

 

d)         The source will comply with an alternative measure, imposed by the Agency or Board, designed to offset any emission increases beyond permitted levels not directly offset by the source.

 

(Source:  Added at 17 Ill. Reg. 6973, effective April 30, 1993)

 

Section 203.1000  Incorporations by Reference

 

The following materials are incorporated by reference.  These incorporations by reference do not include any later amendments or editions.

 

a)         40 CFR Part 51, Subpart I (2021)

 

b)         40 CFR 52.21 (2021)

 

c)         40 CFR Part 51, Appendix S (2021)

 

d)         40 CFR Part 51, Appendix W (2021)

 

e)         40 CFR Part 60 (2021)

 

f)         40 CFR Part 61 (2021)

 

g)         40 CFR Part 62 (2021)

 

h)         40 CFR Part 63 (2021)

 

i)          40 CFR Part 81 (2021)

 

j)          Standard Industrial Classification Manual, 1972, as amended by the 1977 Supplement (U.S.  Government Printing Office stock numbers 4101-0066 and 003-005-00176-0, respectively).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1010  Abbreviations and Acronyms

 

The following abbreviations and acronyms are used in this Part:

 

µg/m3	micrograms per cubic meter
Act	Illinois Environmental Protection Act
Agency	Illinois Environmental Protection Agency
BACT	Best Available Control Technology
Board	Illinois Pollution Control Board
Btu	British Thermal Units
CAA	Clean Air Act
CAAPP	Clean Air Act Permit Program
CEMS	Continuous Emissions Monitoring System
CERMS	Continuous Emissions Rate Monitoring System
CFR	Code of Federal Regulations
CO	carbon monoxide
CO2	carbon dioxide
CPMS	Continuous Parameter Monitoring System
FR	Federal Register
LAER	Lowest Achievable Emission Rate
MW	megawatts
NAAQS	National Ambient Air Quality Standards
NAICS	North American Industry Classification System
NO2	nitrogen dioxide
NOX	nitrogen oxides
NSPS	New Source Performance Standards
NSR	New Source Review
NA NSR	Nonattainment New Source Review
O2	oxygen
PAL	Plantwide Applicability Limitation
PEMS	Predictive Emissions Monitoring System
PM2.5	Particulate Matter equal to or less than 2.5 microns in diameter (Fine Particulate Matter)
PM10	Particulate Matter equal to or less than 10 microns in diameter
PSD	Prevention of Significant Deterioration
RACT	Reasonably Available Control Technology
SIC	Standard Industrial Classification
SIP	State Implementation Plan
SO2	sulfur dioxide
tpy	tons per year
US	United States
U.S.C.	United States Code
USEPA	United States Environmental Protection Agency
VOM	Volatile Organic Material

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1020  Severability

 

If any provision of this Part, or the application of that provision to any person or circumstance, is held invalid, the remainder of this Part, or the application of the provision to persons or circumstances other than those as to which it is held invalid, shall not be affected by that holding.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1030  Definitions

 

Unless otherwise specified in this Part, terms used in this Part have the same meaning as the terms used in 35 Ill. Adm. Code Part 211.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1040  Actual Emissions

 

a)         "Actual Emissions" means the actual rate of emissions of a regulated NSR pollutant from an emissions unit as determined in compliance with subsections (b) through (c), except that this definition shall not apply for calculating whether a significant emissions increase has occurred, or for establishing a PAL under Subpart Q. Instead, Section 203.1070 and Section 203.1320 shall apply for those purposes.

 

b)         In general, actual emissions as of a particular date shall equal the average rate, in tons per year, at which the unit actually emitted the pollutant during a consecutive 24-month period which precedes the particular date and which is representative of normal source operation. The Agency shall allow the use of a different time period upon a demonstration by the applicant to the Agency that the time period is more representative of normal source operation. Such demonstration may include, but need not be limited to, operating records or other documentation of events or circumstances indicating that the preceding 24-month period is not representative of normal source operations. Actual emissions shall be calculated using the unit's actual operating hours, production rates, and types of materials processed, stored or combusted during the selected time period.

 

c)         For any emissions unit which has not begun normal operations on the particular date, actual emissions shall equal the potential to emit of the unit on that date.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1050  Allowable Emissions

 

"Allowable emissions" means the emissions rate of a stationary source calculated using the maximum rated capacity of the source (unless the source is subject to federally enforceable limits which restrict the operating rate, or hours of operation, or both) and the most stringent of the following:

 

a)         The applicable standards set forth in 40 CFR Parts 60, 61, 62 and 63, incorporated by reference in Section 203.1000;

 

b)         The applicable SIP emissions limitation, including those with a future compliance date; or

 

c)         The emissions rate specified as a federally enforceable permit condition, including those with a future compliance date.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1060  Available Growth Margin

 

"Available growth margin" means the portion which remains of any emission allowance for new or modified major stationary sources expressly identified in the attainment demonstration approved by the USEPA under section 172(c)(4) of the CAA (42 U.S.C. 7502(c)(4)) for a particular pollutant and area in a zone (within a nonattainment area) to which economic development should be targeted, in compliance with section 173(a)(1)(B) of the CAA (42 U.S.C. 7503(a)(1)(B)).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1070  Baseline Actual Emissions

 

"Baseline actual emissions" means the rate of emissions, in tons per year, of a regulated NSR pollutant, as determined in accordance with subsections (a) through (d).

 

a)         For any existing electric utility steam generating unit, baseline actual emissions means the average rate, in tons per year, at which the unit actually emitted the pollutant during any consecutive 24-month period selected by the owner or operator within the 5-year period immediately preceding when the owner or operator begins actual construction of the project. The Agency shall allow the use of a different time period upon a determination that it is more representative of normal source operation.

 

1)         The average rate shall include fugitive emissions to the extent quantifiable, and emissions associated with startups, shutdowns, and malfunctions.

 

2)         The average rate shall be adjusted downward to exclude any non-compliant emissions that occurred while the source was operating above any emission limitation that was legally enforceable during the consecutive 24-month period.

 

3)         For a regulated NSR pollutant, when a project involves multiple emissions units, only one consecutive 24-month period must be used to determine the baseline actual emissions for the emissions units being changed. A different consecutive 24-month period can be used for each regulated NSR pollutant.

 

4)         The average rate shall not be based on any consecutive 24-month period for which there is inadequate information for determining annual emissions, in tons per year, and for adjusting this amount if required by subsection (a)(2).

 

b)         For an existing emissions unit (other than an electric utility steam generating unit), baseline actual emissions means the average rate, in tons per year, at which the emissions unit actually emitted the pollutant during any consecutive 24-month period selected by the owner or operator within the 10-year period immediately preceding either the date the owner or operator begins actual construction of the project, or the date a complete permit application is received by the Agency for a permit required by the SIP, whichever is earlier, except that the 10-year period shall not include any period earlier than November 15, 1990.

 

1)         The average rate shall include fugitive emissions to the extent quantifiable, and emissions associated with startups, shutdowns, and malfunctions.

 

2)         The average rate shall be adjusted downward to exclude any non-compliant emissions that occurred while the source was operating above an emission limitation that was legally enforceable during the consecutive 24-month period.

 

3)         The average rate shall be adjusted downward to exclude any emissions that would have exceeded an emission limitation with which the major stationary source must currently comply, had such major stationary source been required to comply with such limitations during the consecutive 24-month period. "Currently" in the context of a contemporaneous emissions change refers to limitations on emissions and source operation that existed just prior to the date of the contemporaneous change. However, if an emission limitation is part of a Maximum Achievable Control Technology standard that the USEPA proposed or promulgated under 40 CFR Part 63 (incorporated by reference in Section 203.1000), the baseline actual emissions need only be adjusted if the Agency has taken credit for such emissions reductions in an attainment demonstration or maintenance plan consistent with the requirements of Section 203.1810(g)(2).

 

4)         For a regulated NSR pollutant, when a project involves multiple emissions units, only one consecutive 24-month period must be used to determine the baseline actual emissions for all the emissions units being changed. A different consecutive 24-month period can be used for each regulated NSR pollutant.

 

5)         The average rate shall not be based on any consecutive 24-month period for which there is inadequate information for determining annual emissions, in tons per year, and for adjusting this amount if required by subsections (b)(2) and (b)(3).

 

c)         For a new emissions unit, the baseline actual emissions for purposes of determining the emissions increase that will result from the initial construction and operation of such unit shall equal zero.  Thereafter, for all other purposes, it shall equal the unit's potential to emit.

 

d)         For a PAL for a stationary source, the baseline actual emissions shall be calculated for existing electric utility steam generating units in accordance with the procedures contained in subsection (a), for other existing emissions units in accordance with the procedures contained in subsection (b), and for a new emissions unit in accordance with the procedures contained in subsection (c).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1080  Begin Actual Construction

 

"Begin actual construction" means in general, initiation of physical on-site construction activities on an emissions unit that are of a permanent nature.  Such activities include, but not limited to, installation of building supports and foundations, laying of underground pipework, and construction of permanent storage structures.  With respect to a change in method of operations, this term refers to those on-site activities other than preparatory activities which mark the initiation of the change.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1090  Building, Structure, Facility, or Installation

 

a)         "Building, structure, facility, or installation" mean all of the pollutant-emitting activities which belong to the same industrial grouping, are located on one or more contiguous or adjacent properties, and are under the control of the same person (or persons under common control).  Pollutant-emitting activities shall be considered as part of the same industrial grouping if they belong to the same "Major Group" (i.e., have the same first two-digit code) as described in the Standard Industrial Classification Manual (incorporated by reference in Section 203.1000).

 

b)         Notwithstanding the provisions of subsection (a), building, structure, facility, or installation means, for onshore activities under Standard Industrial Classification (SIC) Major Group 13: Oil and Gas Extraction, incorporated by reference in Section 203.1000, all of the pollutant-emitting activities included in Major Group 13 that are located on one or more contiguous or adjacent properties, and are under the control of the same person (or persons under common control).  Pollutant emitting activities shall be considered adjacent if they are located on the same surface site, or if they are located on surface sites that are located within ¼ mile of one another (measured from the center of the equipment on the surface site) and they share equipment.  Shared equipment includes, but is not limited to, produced fluids storage tanks, phase separators, natural gas dehydrators or emissions control devices.  Surface site, as used in this subsection, has the same meaning as in 40 CFR 63.761.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1100  Commence

 

"Commence," as applied to construction of a major stationary source or major modification, means that the owner or operator has all necessary preconstruction approvals or permits and either has:

 

a)         Begun, or caused to begin, a continuous program of actual on-site construction of the source, to be completed within a reasonable time; or

 

b)         Entered into binding agreements or contractual obligations, which cannot be cancelled or modified without substantial loss to the owner or operator, to undertake a program of actual construction of the source to be completed within a reasonable time.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1110  Complete

 

"Complete" means, in reference to an application for a permit, that the application contains all of the information necessary for processing the application.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1120  Construction

 

"Construction" means any physical change or change in the method of operation (including fabrication, erection, installation, demolition, or modification of an emissions unit) that would result in a change in emissions.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1130  Dispersion Technique

 

a)         "Dispersion technique" means any technique that attempts to affect the concentration of a pollutant in the ambient air by:

 

1)         Using the portion of a stack that exceeds good engineering practice stack height;

 

2)         Varying the rate of emission of a pollutant according to atmospheric conditions or ambient concentrations of that pollutant; or

 

3)         Increasing final exhaust gas plume rise by:

 

A)        Manipulating source process parameters, exhaust gas parameters, or stack parameters;

 

B)        Combining exhaust gases from several existing stacks into one stack; or

 

C)        Other selective handling of exhaust gas streams so as to increase the exhaust gas plume rise.

 

b)         "Dispersion technique" does not include:

 

1)         The reheating of a gas stream, following use of a pollution control system, for the purpose of returning the gas to the temperature at which it was originally discharged from the stationary source generating the gas stream;

 

2)         The merging of exhaust gas streams when:

 

A)        The source owner or operator demonstrates that the stationary source was originally designed and constructed with such merged gas streams;

 

B)        After July 8, 1985, the merging is part of a change in operation at the stationary source that includes the installation of pollution controls and is accompanied by a net reduction in the allowable emissions of a pollutant. This exclusion from the definition of dispersion techniques shall apply only to the emission limitation for the pollutant affected by the change in operation; or

 

C)        Before July 8, 1985, such merging was part of a change in operation at the stationary source that included the installation of emissions control equipment or was carried out for sound economic or engineering reasons. When there was an increase in the emission limitation or, in the event that no emission limitation was in existence prior to the merging, an increase in the quantity of pollutants actually emitted prior to the merging, the Agency shall presume that merging was significantly motivated by an intent to gain emissions credit for greater dispersion. Absent a demonstration by the source owner or operator that merging was not significantly motivated by such intent, the Agency shall deny credit for the effects of the merging in calculating the allowable emissions for the source;

 

3)         Smoke management in agricultural or silvicultural prescribed burning programs;

 

4)         Episodic restrictions on residential wood burning and open burning; or

 

5)         Techniques under subsection (a)(3) that increase final exhaust gas plume rise when the resulting allowable emissions of SO₂ from the stationary source do not exceed 5,000 tpy.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1140  Electric Utility Steam Generating Unit

 

"Electric utility steam generating unit" means any steam electric generating unit that is constructed for the purpose of supplying more than one-third of its potential electric output capacity and more than 25 MW electrical output to any utility power distribution system for sale. Any steam supplied to a steam distribution system for the purpose of providing steam to a steam-electric generator that would produce electrical energy for sale is also considered in determining the electrical energy output capacity of the affected facility.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1150  Emission Offset

 

"Emission offset" means a creditable emissions reduction used to compensate for the increase in emissions resulting from a new major stationary source or a major modification in accordance with Section 203.1810.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1160  Emissions Unit

 

"Emissions unit" means any part of a stationary source that emits or would have the potential to emit any regulated NSR pollutant and includes an electric utility steam generating unit as defined in Section 203.1140. For purposes of this Part, there are two types of emissions units.

 

a)         A new emissions unit is any emissions unit that is (or will be) newly constructed and that has existed for less than 2 years from the date such emissions unit first operated.

 

b)         An existing emissions unit is any emissions unit that does not meet the requirements of subsection (a). A replacement unit, as defined in Section 203.1350, is an existing emissions unit.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1170  Excessive Concentration

 

"Excessive concentration" is defined for the purposes of determining good engineering practice stack height under Section 203.1200(a)(3) and means:

 

a)         For sources seeking credit for stack height exceeding that established under Section 203.1200(a)(2), a maximum ground-level concentration due to emissions from a stack due in whole or part to downwash, wakes, and eddy effects produced by nearby structures or nearby terrain features that individually is at least 40% in excess of the maximum concentration experienced in the absence of such downwash, wakes, or eddy effects and that contributes to a total concentration due to emissions from all sources that is greater than an ambient air quality standard. For sources subject to this Part, an excessive concentration alternatively means a maximum ground-level concentration due to emissions from a stack due in whole or part to downwash, wakes, or eddy effects produced by nearby structures or nearby terrain features that individually is at least 40% in excess of the maximum concentration experienced in the absence of the downwash, wakes, or eddy effects and greater than an ambient air increment under 35 Ill. Adm. Code 204.900. The allowable emission rate to be used in making demonstrations of excessive concentration shall be prescribed by the NSPS that is applicable to the source category unless the owner or operator demonstrates that this emission rate is infeasible. When those demonstrations are approved by the Agency, an alternative emission rate shall be established in consultation with the source owner or operator.

 

b)         For sources seeking credit for increases in existing stack heights up to the heights established under Section 203.1200(a)(2), either:

 

1)         A maximum ground-level concentration due in whole or part to downwash, wakes or eddy effects as provided in subsection (a), except that the emission rate specified by the SIP (or, in the absence of such a limit, the actual emission rate) shall be used; or

 

2)         The actual presence of a local nuisance caused by the existing stack, as determined by the Agency; and

 

c)         For sources seeking credit for a stack height determined under Section 203.1200(a)(2) when the Agency requires the use of a field study or fluid model to verify good engineering practice stack height, for sources seeking stack height credit based on the aerodynamic influence of cooling towers, and for sources seeking stack height credit based on the aerodynamic influence of structures not adequately represented by the equations in Section 203.1200(a)(2), a maximum ground-level concentration due in whole or part to downwash, wakes or eddy effects that is at least 40% in excess of the maximum concentration experienced in the absence of such downwash, wakes, or eddy effects.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1180  Federally Enforceable

 

"Federally enforceable" means all limitations and conditions which are enforceable by the USEPA, including those requirements developed pursuant to 40 CFR Parts 60, 61, 62 and 63 (incorporated by reference in Section 203.1000), requirements within the SIP, any permit requirements established pursuant to 40 CFR 52.21 (incorporated by reference in Section 203.1000) or this Part or under regulations approved pursuant to 40 CFR Part 51, Subpart I (incorporated by reference in Section 203.1000), including operating permits issued under an USEPA-approved program that is incorporated into the SIP and expressly requires adherence to any permit issued under such program.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1190  Fugitive Emissions

 

"Fugitive emissions" means those emissions which could not reasonably pass through a stack, chimney, vent or other functionally equivalent opening.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1200  Good Engineering Practice

 

a)         "Good engineering practice", with respect to stack height, means the greater of:

 

1)         65 meters, measured from the ground-level elevation at the base of the stack;

 

2)         The following:

 

A)        For a stack in existence on January 12, 1979, and for which the owner or operator had obtained all necessary preconstruction approvals or permits required under 40 CFR Parts 51 and 52 (incorporated by reference in 35 Ill. Adm. Code 204.100):

 

H_g = 2.5H,

 

provided the owner or operator produces evidence that this equation was actually relied on in establishing an emission limitation;

 

B)        For all other stacks:

 

H_g = H + 1.5L

 

where:

 

Hg	=	good engineering practice stack height, measured from the ground-level elevation at the base of the stack;
H	=	height of nearby structure or structures measured from the ground-level elevation at the base of the stack;
L	=	lesser dimension, height or projected width, of nearby structure or structures provided that USEPA or the Agency may require the use of a field study or fluid model to verify good engineering practice stack height for the source; or

 

3)         The height demonstrated by a fluid model or a field study approved by USEPA or the Agency that ensures the emissions from a stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures, or nearby terrain features.

 

b)         For purposes of this definition, "stack" means any point in a source designed to emit solids, liquids, or gases into the air, including a pipe or duct but not including flares.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1210  Lowest Achievable Emission Rate

 

"Lowest Achievable Emission Rate" or "LAER" means, for any source, the more stringent rate of emissions based on the following:

 

a)         The most stringent emissions limitation which is contained in the implementation plan of any State for such class or category of stationary source, unless the owner or operator of the proposed stationary source demonstrates that such limitations are not achievable; or

 

b)         The most stringent emissions limitation which is achieved in practice by such class or category of stationary sources. This limitation, when applied to a modification, means the lowest achievable emissions rate for the new or modified emissions units within the stationary source. In no event shall the application of this term permit a proposed new or modified stationary source to emit any pollutant in excess of the amount allowable under an applicable new source performance standard adopted by the USEPA under section 111 of the CAA and made applicable in Illinois under Section 9.1 of the Act.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1220  Major Modification

 

a)         Except as provided in subsections (d) through (f) below, "major modification" means any physical change or change in the method of operation of a major stationary source that would result in: a significant emissions increase (as defined in Section 203.1380) of a regulated NSR pollutant (as defined in Section 203.1340); and a significant net emissions increase of that regulated NSR pollutant for which the source is a major stationary source.

 

b)         Any significant emissions increase (as defined in Section 203.1380) from any emissions units or net emissions increase (as defined in Section 203.1260) at a major stationary source that is significant for VOM or NO_X shall be considered significant for ozone.

 

c)         A physical change or change in the method of operation shall not include:

 

1)         Routine maintenance, repair and replacement;

 

2)         Use of an alternative fuel or raw material by reason of:

 

A)        An order under Section 2(a) and (b) of the Energy Supply and Environmental Coordination Act of 1974 (15 U.S.C. 791) (or any superseding legislation); or

 

B)        A natural gas curtailment plan under the Federal Power Act (16 U.S.C. 791);

 

3)         Use of an alternative fuel by reason of an order or rule under section 125 of the CAA (42 U.S.C. 7425);

 

4)         Use of an alternative fuel at a steam generating unit to the extent that the fuel is generated from municipal solid waste;

 

5)         Use of an alternative fuel or raw material by a stationary source which:

 

A)        The source was capable of accommodating before December 21, 1976, unless such change would be prohibited under any federally enforceable permit condition which was established after December 21, 1976, pursuant to 40 CFR 52.21, 35 Ill. Adm. Code 204, this Part, or 35 Ill. Adm. Code 201.142 or 201.143; or

 

B)        The source is approved to use under any permit issued under 40 CFR 52.21, this Part, 35 Ill. Adm. Code 204, or 35 Ill. Adm. Code 201.142 or 201.143;

 

6)         An increase in the hours of operation or in the production rate, unless such change is prohibited under any enforceable permit condition which was established after December 21, 1976 pursuant to 40 CFR 52.21, 35 Ill. Adm. Code 204, this Part, or 35 Ill. Adm. Code 201.142 or 201.143; or

 

7)         Any change in ownership at a stationary source.

 

d)         In the case of any major stationary source of VOM or NO_X located in an area classified as serious or severe nonattainment for ozone (other than a source which emits or has the potential to emit 100 tons or more of VOM or NO_X per year), whenever any change at that source results in a significant increase in emissions of VOM or NO_X, respectively, from any discrete operation, unit, or other pollutant emitting activity at the source, such increase shall be considered a major modification for purposes of this Part, except such increase shall not be considered a major modification for such purposes if the owner or operator of the source elects to offset the increase by a greater reduction in emissions of VOM or NO_X, respectively, from other operations, units, or activities within the source at an internal offset ratio of at least 1.3 to 1.

 

e)         In areas classified as extreme nonattainment for ozone, beginning on the date that an area is classified by the USEPA as an extreme nonattainment area for ozone, any physical change in or change in the method of operation of a major stationary source which results in any increase in emissions of VOM or NO_X from a discrete operation, unit, or other pollutant emitting activity shall be considered a major modification.

 

f)         This definition shall not apply with respect to a particular regulated NSR pollutant when the major stationary source is complying with the requirements under Subpart Q for a PAL for that pollutant. Instead, the definition at Section 203.2230 will apply.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1230  Major Stationary Source

 

a)         The following constitute a major stationary source:

 

1)         For an area designated as nonattainment for ozone, a major stationary source for ozone is a stationary source which emits or has the potential to emit VOM in an amount equal to or greater than the following:

 

A)        100 tpy in an area classified as marginal or moderate nonattainment for ozone;

 

B)        50 tpy in an area classified as serious nonattainment for ozone;

 

C)        25 tpy in an area classified as severe nonattainment for ozone; and

 

D)        10 tpy in an area classified as extreme nonattainment for ozone.

 

2)         For an area designated as nonattainment for ozone, a major stationary source for ozone is a stationary source which emits or has the potential to emit NO_X in an amount equal to or greater than the following, unless the USEPA has made a finding under sections 110 and 182(f) of the CAA (42 U.S.C. 7410, 7511a(f)) that controlling of emissions of NO_X from such source shall not be required:

 

A)        100 tpy in an area classified as marginal or moderate nonattainment for ozone;

 

B)        50 tpy in an area classified as serious nonattainment for ozone;

 

C)        25 tpy in an area classified as severe nonattainment for ozone; and

 

D)        10 tpy in an area classified as extreme nonattainment for ozone.

 

3)         For an area designated nonattainment for PM₁₀, a major stationary source is a stationary source which emits or has the potential to emit:

 

A)        100 tpy or more of PM₁₀ in an area classified as moderate nonattainment for PM₁₀; and

 

B)        70 tpy or more of PM₁₀ in an area classified as serious nonattainment for PM₁₀.

 

4)         For an area designated nonattainment for PM_2.5, a major stationary source is a stationary source which emits or has the potential to emit:

 

A)        100 tpy or more of direct PM_2.5 emissions in an area classified as moderate nonattainment for PM_2.5;

 

B)        100 tpy or more of any individual precursor for PM_2.5 (as required in Section 203.1340) in an area classified as moderate nonattainment for PM_2.5;

 

C)        70 tpy or more of direct PM_2.5 emissions in an area classified as serious nonattainment for PM_2.5; and

 

D)        70 tpy or more of any individual precursor for PM_2.5 (as required in Section 203.1340), in an area classified as serious nonattainment for PM_2.5.

 

5)         For an area designated nonattainment for CO, a major stationary source is a stationary source which emits or has the potential to emit:

 

A)        100 tpy or more in an area classified as moderate nonattainment for CO, except as provided in subsection (a)(5)(B);

 

B)        50 tpy or more in an area classified as serious nonattainment for CO where stationary sources significantly contribute to ambient CO levels, as determined under rules issued by the USEPA, under the CAA.

 

6)         For an area designated as nonattainment for NO₂, a major stationary source is a stationary source which emits or has the potential to emit 100 tpy or more of NO_X.

 

7)         For an area designated nonattainment for a pollutant other than those pollutants addressed in subsections (a)(1) through (a)(6) above, a major stationary source is a stationary source which emits or has the potential to emit 100 tpy or more of the pollutant.

 

8)         For stationary sources locating outside designated nonattainment areas for purposes of Subpart R, a major stationary source is a stationary source which emits or has the potential to emit 100 tpy or more of a regulated NSR pollutant.

 

b)         Any physical change that occurs at a stationary source which does not qualify under subsection (a) as a major stationary source will be considered a major stationary source, if the change would constitute a major stationary source by itself.

 

c)         The fugitive emissions of a stationary source shall not be included in determining for any purposes of this Section whether it is a major stationary source, unless the source belongs to one of the following categories of stationary sources:

 

1)         Coal cleaning plants (with thermal dryers);

 

2)         Kraft pulp mills;

 

3)         Portland cement plants;

 

4)         Primary zinc smelters;

 

5)         Iron and steel mills;

 

6)         Primary aluminum ore reduction plants;

 

7)         Primary copper smelters;

 

8)         Municipal incinerators capable of charging more than 50 tons of refuse per day;

 

9)         Hydrofluoric, sulfuric, or nitric acid plants;

 

10)       Petroleum refineries;

 

11)       Lime plants;

 

12)       Phosphate rock processing plants;

 

13)       Coke oven batteries;

 

14)       Sulfur recovery plants;

 

15)       Carbon black plants (furnace process);

 

16)       Primary lead smelters;

 

17)       Fuel conversion plants;

 

18)       Sintering plants;

 

19)       Secondary metal production plants;

 

20)       Chemical process plants—The term "chemical processing plant" shall not include ethanol production facilities that produce ethanol by natural fermentation included in NAICS codes 325193 or 312140;

 

21)       Fossil-fuel boilers (or combination thereof) totaling more than 250 million Btu per hour heat input;

 

22)       Petroleum storage and transfer units with a total storage capacity exceeding 300,000 barrels;

 

23)       Taconite ore processing plants;

 

24)       Glass fiber processing plants;

 

25)       Charcoal production plants;

 

26)       Fossil fuel-fired steam electric plants of more than 250 million Btu per hour heat input; and

 

27)       Any other stationary source categories which, as of August 7, 1980, is being regulated by a standard promulgated under section 111 or 112 of the CAA (42 U.S.C. 7411, 7412), but only with respect to those air pollutants that have been regulated for that category.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1240  Nearby

 

"Nearby", with respect to a specific structure or terrain feature:

 

a)         For purposes of applying the formula provided in Section 203.1200(a)(2), means that distance up to five times the lesser of the height or the width dimension of a structure, but not greater than 0.8 km (½ mile); and

 

b)         For conducting demonstrations under Section 203.1200(a)(3), means not greater than 0.8 km (½ mile), except that a portion of a terrain feature may be considered to be nearby if it falls within a distance of up to 10 times the maximum height of the feature, not to exceed 2 miles if such feature achieves a height, 0.8 km from the stack, that is at least 40 percent of the good engineering practice stack height determined by the formula provided in Section 203.1200(a)(2)(B) or 26 meters, whichever is greater, as measured from the ground-level elevation at the base of the stack. The height of the structure or terrain feature is measured from the ground-level elevation at the base of the stack.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1250  Necessary Preconstruction Approvals or Permits

 

"Necessary preconstruction approvals or permits" mean those permits or approvals required under federal air quality control laws and regulations and those air quality control laws and regulations which are part of the applicable SIP.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1260  Net Emissions Increase

 

a)         "Net emissions increase" means, with respect to any regulated NSR pollutant emitted by a major stationary source, the amount by which the sum of the following exceeds zero:

 

1)         The increase in emissions from a particular physical change or change in the method of operation at a stationary source as calculated pursuant to Section 203.1410(c); and

 

2)         Any other increases and decreases in actual emissions at the major stationary source that are contemporaneous with the particular change and are otherwise creditable. Baseline actual emissions for calculating increases and decreases under this Section shall be determined as provided in Section 203.1070, except that Section 203.1070(a)(3) and Section 203.1070(b)(4) shall not apply.

 

b)         The following steps determine whether the increase or decrease in emissions is available.

 

1)         Except for increases or decreases in VOM and NO_X emissions in serious and severe ozone nonattainment areas which are addressed in Section 203.1370(c), an increase or decrease in actual emissions is contemporaneous only if it occurs between the date that an increase from a particular change occurs and the date five years before a timely and complete application is submitted for the particular change.  It shall also occur after either April 24, 1979, or the date the area is designated by the USEPA as a nonattainment area for the pollutant, whichever is more recent.

 

2)         An increase or decrease in actual emissions is creditable:

 

A)        Only if there is not in effect for the source at the time the particular change occurs, a permit issued under this Part which relied on the same increase or decrease in actual emissions; and

 

B)        Only to the extent the new and old levels differ.

 

3)         A decrease in actual emissions is creditable only to the extent that:

 

A)        It is enforceable as a practical matter at and after the time that actual construction on the particular change begins;

 

B)        It has approximately the same qualitative significance for public health and welfare as that attributed to the increase from the particular change;

 

C)        The old level of actual emissions or the old level of allowable emissions, whichever is lower, exceeds the new level of actual emissions; and

 

D)        The Agency has not relied on it in issuing any permit under 35 Ill.  Adm.  Code 201.142 or 201.143 or this Part or 35 Ill. Adm. Code 204 or 40 CFR 52.21 and has not relied on it for demonstrating attainment or reasonable further progress.

 

4)         An increase that results from a physical change at a source occurs when the emissions unit on which construction occurred becomes operational and begins to emit a particular pollutant.  Any emission unit that replaces an existing emissions unit that requires shakedown becomes operational only after a shakedown period, not to exceed 180 days.

 

5)         Section 203.1040(b) shall not apply for determining creditable increases and decreases after a change.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1270  Nonattainment Area

 

An area designated by the USEPA as nonattainment for a given pollutant under section 107 of the CAA (42 U.S.C. 7407) in Subpart C of 40 CFR Part 81.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1280  Nonattainment New Source Review (NA NSR) Permit

 

"Nonattainment New Source Review permit" or "NA NSR permit" means a permit or a portion of a permit for a new major source or major modification that is issued by the Agency under the construction permit program required by Section 9.1(c) of the Act that has been approved by USEPA and incorporated into the Illinois SIP to implement the requirements of section 173 of the CAA and 40 CFR 51.165. [415 ILCS 5/3.298]

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1290  Potential to Emit

 

"Potential to emit" means the maximum capacity of a stationary source to emit a pollutant under its physical and operational design.  Any physical or operational limitation on the capacity of the source to emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design only if the limitation or the effect it would have on emissions is federally enforceable or legally and practicably enforceable by a state or local air pollution control agency.  Secondary emissions do not count in determining the potential to emit of a stationary source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1300  Process Unit

 

"Process unit" means any collection of structures and/or equipment that processes, assembles, applies, blends, or otherwise uses material inputs to produce or store an intermediate or completed product. A process unit may contain more than one emissions unit.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1310  Project

 

"Project" means a physical change in or change in the method of operation of an existing major stationary source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1320  Projected Actual Emissions

 

a)         "Projected actual emissions" means the maximum annual rate, in tons per year, at which an existing emissions unit is projected to emit a regulated NSR pollutant in any one of the 5 years (12-month period) following the date the unit resumes regular operation after the project, or in any one of the 10 years following that date, if the project involves increasing the emissions unit's design capacity or its potential to emit that regulated NSR pollutant and full utilization of the unit would result in a significant emissions increase or a significant net emissions increase at the major stationary source.

 

b)         In determining the projected actual emissions under subsection (a) (before beginning actual construction), the owner or operator of the major stationary source:

 

1)         Shall consider all relevant information, including, but not limited to, historical operational data, the company's own representations, the company's expected business activity and the company's highest projections of business activity, the company's filings with the State or federal regulatory authorities, and compliance plans under Illinois' SIP; and

 

2)         Shall include fugitive emissions to the extent quantifiable, and emissions associated with startups, shutdowns, and malfunctions; and

 

3)         Shall exclude, in calculating any increase in emissions that results from the particular project, that portion of the unit's emissions following the project that an existing unit could have accommodated during the consecutive 24-month period used to establish the baseline actual emissions under Section 203.1070 and that are also unrelated to the particular project, including any increased utilization due to product demand growth; or

 

4)         In lieu of using the method set out in subsections (b)(1) through (b)(3), may elect to use the emissions unit's potential to emit, in tons per year, as defined under Section 203.1290.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1330  Reasonable Further Progress

 

"Reasonable further progress" means the annual incremental reductions in the emissions of the pollutant as determined by the USEPA pursuant to Part D of Title I of the CAA (42 U.S.C. 7501 et seq.) and federal regulations adopted pursuant thereto.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1340  Regulated NSR Pollutant

 

"Regulated NSR pollutant" means the following:

 

a)         NO_X or VOM;

 

b)         Any pollutant for which a NAAQS has been promulgated;

 

c)         Any pollutant that is identified under this Section as a constituent or precursor of a general pollutant listed under subsection (a) or (b), provided that such constituent or precursor pollutant may only be regulated under NSR as part of regulation of the general pollutant.  Precursors for purposes of NSR are the following:

 

1)         Except as provided in Section 203.1450, VOM and NO_X are precursors to ozone in all ozone nonattainment areas.

 

2)         SO₂ and NO_X are precursors to PM_2.5 for a stationary source located in a PM_2.5 nonattainment area or, for purposes of Subpart R, a stationary source which would cause or contribute to a violation of a PM_2.5 NAAQS.

 

3)         VOM and ammonia are precursors to PM_2.5 in any PM_2.5 nonattainment area.

 

d)         Direct PM_2.5 emissions and PM₁₀ emissions shall include gaseous emissions from a source or activity that condense to form particulate matter at ambient temperatures.  On or after January 1, 2011, such condensable particulate matter shall be accounted for in applicability determinations and in establishing emissions limitations for direct PM_2.5 emissions and PM₁₀ emissions in NA NSR permits.  Compliance with emissions limitations for direct PM_2.5 emissions and PM₁₀ emissions issued prior to this date shall not be based on condensable particulate matter unless required by the terms and conditions of the permit.  Applicability determinations made prior to this date without accounting for condensable particulate matter shall not be considered as a violation of this Part.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1350  Replacement Unit

 

"Replacement unit" means an emissions unit for which all the criteria listed in subsections (a) through (d) are met. No creditable emissions reductions shall be generated from shutting down the existing emissions unit that is replaced.

 

a)         The emissions unit is a reconstructed unit within the meaning of 40 CFR 60.15(b)(1), or the emissions unit completely takes the place of an existing emissions unit.

 

b)         The emissions unit is identical to or functionally equivalent to the replaced emissions unit.

 

c)         The replacement does not alter the basic design parameter or parameters of the process unit. Basic design parameters of a process unit shall be determined as follows:

 

1)         Except as provided in subsection (c)(3), for a process unit at a steam electric generating facility, the owner or operator may select as its basic design parameters either maximum hourly heat input and maximum hourly fuel consumption rate or maximum hourly electric output rate and maximum steam flow rate.  When establishing fuel consumption specifications in terms of weight or volume, the minimum fuel quality based on Btu content shall be used for determining the basic design parameter or parameters for a coal-fired electric utility steam generating unit.

 

2)         Except as provided in subsection (c)(3), the basic design parameter or parameters for any process unit that is not at a steam electric generating facility are maximum rate of fuel or heat input, maximum rate of material input, or maximum rate of product output.  Combustion process units will typically use maximum rate of fuel input.  For sources having multiple end products and raw materials, the owner or operator should consider the primary product or primary raw material when selecting a basic design parameter.

 

3)         If the owner or operator believes the basic design parameter or parameters in subsections (c)(1) and (c)(2) is not appropriate for a specific industry or type of process unit, the owner or operator may propose to the Agency an alternative basic design parameter or parameters for the source's process unit or units.  If the Agency approves of the use of an alternative basic design parameter or parameters, the Agency shall issue a permit that is legally enforceable, records such basic design parameter or parameters and requires the owner or operator to comply with such parameter or parameters.

 

4)         The owner or operator shall use credible information, such as results of historic maximum capability tests, design information from the manufacturer, or engineering calculations, in establishing the magnitude of the basic design parameter or parameters specified in subsections (c)(1) and (c)(2).

 

5)         If design information is not available for a process unit, then the owner or operator shall determine the process unit's basic design parameter or parameters using the maximum value achieved by the process unit in the five-year period immediately preceding the planned activity.

 

6)         Efficiency of a process unit is not a basic design parameter.

 

d)         The replaced emissions unit is permanently removed from the major stationary source, otherwise permanently disabled, or permanently barred from operation by a permit that is enforceable as a practical matter. If the replaced emissions unit is brought back into operation, it shall constitute a new emissions unit.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1360  Secondary Emissions

 

"Secondary Emissions" means emissions which would occur as a result of the construction or operation of a major stationary source or major modification, but do not come from the major stationary source or major modification itself.  Secondary emissions include emissions from any offsite support facility which would not be constructed or increase its emissions except as a result of the construction or operation of the major stationary source or major modification.  Secondary emissions do not include any emissions which come directly from a mobile source, such as emissions from the tailpipe of a motor vehicle, from a train, or from a vessel.  For the purposes of this Part, secondary emissions must be specific, well defined, quantifiable, and impact the same general area as the major stationary source or major modification which causes the secondary emissions.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1370  Significant

 

a)         "Significant" means, in reference to a net emissions increase or the potential of a source to emit any of the following pollutants, a rate of emissions that would equal or exceed any of the following rates:

 

Pollutant	Emissions Rate
CO	100 tpy of CO, except under subsection (b)
NO2	40 tpy of NOX
SO2	40 tpy of SO2
PM10	15 tpy of PM10
PM2.5	10 tpy of direct PM2.5 emissions; 40 tpy of SO2, 40 tpy of NOX, 40 tpy of VOM, or 40 tpy of ammonia, to the extent that any such pollutant is defined as a precursor for PM2.5 in Section 203.1340.
Ozone	40 tpy of VOM or NOX, except under subsections (c) and (d).
Lead	0.6 tpy

 

b)         For areas classified as serious nonattainment for CO where stationary sources significantly contribute to ambient CO levels, as determined under rules issued by the USEPA, pursuant to the CAA, notwithstanding the significant emissions rate for CO in subsection (a), significant means an increase in actual emissions of CO that would result from any physical change in or change in the method of operation of a major stationary source, if such increase equals or exceeds 50 tpy.

 

c)         For areas classified as serious or severe nonattainment for ozone, notwithstanding the significant emissions rate for ozone in subsection (a), an increase in emissions of VOM or NO_X shall be considered significant if the net emissions increase of such air pollutant from a stationary source located within such area exceeds 25 tons when aggregated with all other net increases in emissions from the source over any period of 5 consecutive calendar years which includes the calendar year in which such increase occurred.  This provision shall become effective beginning November 15, 1992, or such later date when an area is classified as a serious or severe nonattainment area for ozone.

 

d)         For areas classified as extreme nonattainment for ozone, notwithstanding the significant emissions rate for ozone in subsection (a), any increase in emissions of VOM or NO_X from any emissions unit at a major stationary source of VOM or NO_X shall be considered significant.

 

e)         For major stationary sources located outside designated nonattainment areas for purposes of Subpart R, an increase in emissions of a regulated NSR pollutant shall be considered significant if it would equal or exceed the rate listed in subsection (a), notwithstanding the attainment status in the area.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1380  Significant Emissions Increase

 

"Significant emissions increase" means, for a regulated NSR pollutant, an increase in emissions that is significant (as defined in Section 203.1370) for that pollutant.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1390  Stack in Existence

 

"Stack in existence" means that the owner or operator had begun, or caused to begin, a continuous program of physical on-site construction of the stack or entered into binding agreements or contractual obligations, that could not be cancelled or modified without substantial loss to the owner or operator, to undertake a program of construction of the stack to be completed within a reasonable time.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1400  Stationary Source

 

"Stationary source" means any building, structure, facility, or installation which emits or may emit a regulated NSR pollutant.  Emissions resulting directly from an internal combustion engine for transportation purposes or from a nonroad engine or nonroad vehicle as defined in section 216 of the CAA (42 U.S.C. 7550) are not a part of a stationary source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1410  Applicability

 

a)         The requirements of this Part, other than Subpart R, shall apply to the construction of any new major stationary source (as defined in Section 203.1230) or major modification (as defined in Section 203.1220) that is major for the pollutant for which the area is designated nonattainment under section 107(d)(1)(A)(i) of the CAA (42 U.S.C. 7407(d)(1)(A)(i)), if the stationary source or modification would locate anywhere in the designated nonattainment area.  Different pollutants, including individual precursors, are not summed to determine applicability of a major stationary source or major modification.

 

b)         No new major stationary source or major modification to which the requirements of Sections 203.1410, 203.1420, 203.1430, 203.1440, 203.1800, 203.1810, 203.1820, 203.1830, or 203.2000 apply shall begin actual construction without a permit that states that the major stationary source or major modification will meet those requirements.  The Agency has authority to issue any such permit.

 

c)         The requirements of this Part will be applied in accordance with subsections (c)(1) through (c)(6).

 

1)         Except as otherwise provided in subsection (e) and in Sections 203.1220(d) through (e), and consistent with the definition of major modification contained in Section 203.1220, a project is a major modification for a regulated NSR pollutant if it causes two types of emissions increases: a significant emissions increase (as defined in Section 203.1380), and a significant net emissions increase (as defined in Section 203.1260 and Section 203.1370). The project is not a major modification if it does not cause a significant emissions increase. If the project causes a significant emissions increase, then the project is a major modification only if it also results in a significant net emissions increase.

 

2)         The procedure for calculating (before beginning actual construction) whether a significant emissions increase (i.e., the first step of the process) will occur depends upon the type or types of emissions units involved in the project, according to subsections (c)(3) through (c)(5). The procedure for calculating (before beginning actual construction) whether a significant net emissions increase will occur at the major stationary source (i.e., the second step of the process) is contained in the definition in Section 203.1260. Regardless of any such preconstruction projections, a major modification results if the project causes a significant emissions increase and a significant net emissions increase.

 

3)         Actual-to-Projected-Actual Applicability Test for Projects That Only Involve Existing Emissions Units. A significant emissions increase of a regulated NSR pollutant is projected to occur if the sum of the difference between the projected actual emissions (as defined in Section 203.1320) and the baseline actual emissions (as defined in Section 203.1070), for each existing emissions unit, equals or exceeds the significant amount for that pollutant (as defined in Section 203.1370).

 

4)         Actual-to-Potential Test for Projects That Only Involve Construction of a New Emissions Unit or Units. A significant emissions increase of a regulated NSR pollutant is projected to occur if the sum of the difference between the potential to emit (as defined in Section 203.1290) from each new emissions unit following completion of the project and the baseline actual emissions (as defined in Section 203.1070) of these units before the project equals or exceeds the significant amount for that pollutant (as defined in Section 203.1370).

 

5)         Hybrid Test for Projects That Involve Multiple Types of Emissions Units. A significant emissions increase of a regulated NSR pollutant is projected to occur if the sum of the difference for all emissions units, using the method specified in subsections (c)(3) and (c)(4) as applicable with respect to each emissions unit, equals or exceeds the significant amount for that pollutant (as defined in Section 203.1370).

 

6)         The "sum of the difference" as used in subsections (c)(3) through (c)(5) shall include both increases and decreases in emissions calculated in compliance with those subsections.

 

d)         Except as otherwise provided in Section 203.1700(f)(2), the provisions of Section 203.1700 apply with respect to any regulated NSR pollutant emitted from projects involving existing emissions units at a major stationary source (other than projects at a source with a PAL) in circumstances in which there is a reasonable possibility, within the meaning of Section 203.1700(f), that a project that is not a part of a major modification may result in a significant emissions increase of such pollutant, and the owner or operator elects to use the method specified in Section 203.1320(b)(1) through (b)(3) for calculating projected actual emissions.

 

e)         For any major stationary source with a PAL for a regulated NSR pollutant, the major stationary source shall comply with requirements under Section 203.2100 through Section 203.2420.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1420  Effect of Permits

 

Approval to construct shall not relieve any owner or operator of the responsibility to comply fully with applicable provisions of the SIP and any other requirements under local, State, or federal law.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1430  Relaxation of a Source-Specific Limitation

 

At such time that a particular source or modification becomes a major stationary source or major modification solely by virtue of a relaxation in any enforceable limitation which was established after August 7, 1980, on the capacity of the source or modification otherwise to emit a pollutant, such as a restriction on hours of operation, then the requirements of this Part shall apply to the source or modification as though construction had not yet commenced on the source or modification.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1440  Prohibitions

 

a)         A major stationary source or major modification shall not violate any condition contained in a construction permit issued for a new major stationary source or major modification which is subject to this Part.

 

b)         In any nonattainment area, no person shall begin actual construction of a new major stationary source or major modification that is major for the regulated NSR pollutant for which the area is designated as nonattainment area under section 107(d)(1)(A)(i) of the CAA (42 U.S.C. 7407(d)(1)(A)(i)), except as in compliance with this Subpart and Subpart N.  Revisions to this Part which were adopted to implement the CAA Amendments of 1990 shall not apply to any new major stationary source or major modification for which a permit application was submitted by June 30, 1992, for PM₁₀; by May 15, 1992, for SO₂; or by November 15, 1992, for VOM and NO_X emissions for sources located in all ozone nonattainment areas.

 

c)         A person shall not cause or allow the operation of a new major stationary source or major modification subject to the requirements of Subpart N, except as in compliance with applicable LAER provisions established under Section 203.1800 for such source or modification.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1450  Control of Ozone, PM₁₀, and PM_2.5

 

a)         The provisions of this Part applicable to major stationary sources and major modifications of VOM shall apply to NO_X emissions from major stationary sources and major modifications of NO_X in any ozone nonattainment area, except in ozone nonattainment areas where the USEPA has granted a NO_X waiver applying the standards under section 182(f) of the CAA (42 U.S.C. 7511a(f)) and the waiver continues to apply.

 

b)         The provisions of this Part applicable to major stationary sources and major modifications of PM₁₀ shall also apply to major stationary sources and major modifications of PM₁₀ precursors, except where the USEPA determines that such sources do not contribute significantly to PM₁₀ levels that exceed the PM₁₀ ambient standards in the area.

 

c)         The control requirements of this Part which are applicable to major stationary sources and major modifications of PM_2.5 shall also apply to major stationary sources and major modifications of PM_2.5 precursors which are regulated NSR pollutants in a PM_2.5 nonattainment area.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1460  Permit Exemption Based on Fugitive Emissions

 

The provisions of this Part shall not apply to a source or modification that would be a major stationary source or major modification only if fugitive emissions, to the extent quantifiable as evidenced by 35 Ill. Adm. Code 201.122, are considered in calculating the potential to emit of the stationary source or modification and the source does not belong to any of the categories enumerated in Section 203.1230(c).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1500  Stack Heights

 

a)         The degree of emission limitation required for control of any regulated NSR pollutant under this Part shall not be affected in any manner by:

 

1)         So much portion of the stack height of any source that exceeds good engineering practice, or

 

2)         Any other dispersion technique.

 

b)         Except as provided in subsection (c), subsection (a) shall not apply with respect to stack heights in existence before December 31, 1970, or to dispersion techniques implemented before then.

 

c)         Notwithstanding subsection (b), subsection (a) shall apply where regulated NSR pollutants are being emitted from such stacks or using such dispersion techniques by sources, as defined in section 111(a)(3) of the CAA (42 U.S.C. 7411(a)(3)), which were constructed, or reconstructed, or for which major modifications were carried out after December 31, 1970.

 

d)         Subsection (a) shall not apply with respect to coal-fired steam electric generating units subject to the provisions of section 118 of the CAA (42 U.S.C. 7418), which commenced operation before July 1, 1957, and whose stacks were constructed under a construction contract awarded before February 8, 1974.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1600  Construction Permit

 

a)         The Agency shall only issue a construction permit for a new major stationary source or a major modification that is subject to the requirements of this Part, other than this Subpart or Subpart R, if the Agency determines all applicable requirements of this Part, other than this Subpart and Subpart R, are satisfied.

 

b)         The Agency shall include in any NA NSR permit conditions specifying the manner in which the applicable requirements of Subpart N apply.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1610  Public Participation

 

a)         Prior to the initial issuance or a modification of a permit issued pursuant to this Part, the Agency shall provide, at a minimum, a notice of the proposed issuance or modification of a permit, a comment period, and opportunity for public hearing pursuant to the Agency's public participation procedures at 35 Ill. Adm. Code 252.

 

b)         In addition to the applicable requirements of 35 Ill. Adm. Code 252:

 

1)         The notice for the comment period or public hearing prepared by the Agency shall include information on how to access the draft permit and the administrative record for the draft permit.

 

2)         The Agency shall also send a copy of this notice to:

 

A)        The USEPA;

 

B)        All other state and local air pollution control agencies having jurisdiction in the region in which such new or modified source would be or is located; and

 

C)        Any other agency in the region having responsibility for implementing the procedures required under this Part.

 

3)         The Project Summary, Statement of Basis or Fact Sheet that accompanies the draft of a permit that would be issued pursuant to this Part or the draft of a modification permit that would be issued pursuant to this Part shall describe the basis of the Agency's proposed decision to grant the permit and include a discussion of the Agency's analysis of the effect of the construction or modification on ambient air quality, including the Agency's proposed action.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1700  Recordkeeping and Reporting Requirements for Certain Projects at Major Stationary Sources in Nonattainment Areas

 

Except as otherwise provided in subsection (f), the provisions of this Section apply with respect to any regulated NSR pollutant emitted from projects involving existing emissions unit or units at a major stationary source in a nonattainment area (other than projects at a source with a PAL) in circumstances where there is a reasonable possibility, within the meaning of subsection (f), that a project that is not a major modification for the pollutant may result in a significant emissions increase of such pollutant, and the owner or operator elects to use the method specified in Section 203.1320(b)(1) through (b)(3) for calculating projected actual emissions.

 

a)         Before beginning actual construction of the project, the owner or operator shall document and maintain a record of the following information:

 

1)         A description of the project;

 

2)         Identification of the emissions unit or units whose emissions of a regulated NSR pollutant could be affected by the project; and

 

3)         A description of the applicability test used to determine that the project is not a major modification for any regulated NSR pollutant, including the baseline actual emissions, the projected actual emissions, the amount of emissions excluded under Section 203.1320(b)(3) and an explanation for why such amount was excluded, and any netting calculations, if applicable.

 

b)         If the emissions unit is an existing electric utility steam generating unit, before beginning actual construction, the owner or operator shall provide a copy of the information set out in subsection (a) to the Agency. Nothing in this subsection shall be construed to require the owner or operator of such a unit to obtain any determination from the Agency before beginning actual construction.

 

c)         The owner or operator shall monitor the emissions of any regulated NSR pollutant that could increase as a result of the project and that is emitted by any emissions unit identified in subsection (a)(2); and calculate and maintain a record of the annual emissions, in tons per year on a calendar year basis, for a period of 5 years following resumption of regular operations after the change, or for a period of 10 years following resumption of regular operations after the change if the project increases the design capacity or potential to emit that regulated NSR pollutant at such emissions unit.

 

d)         If the unit is an existing electric utility steam generating unit, the owner or operator shall submit a report to the Agency within 60 days after the end of each year during which records must be generated under subsection (c) setting out the unit's annual emissions during the calendar year that preceded submission of the report.

 

e)         If the unit is an existing unit other than an electric utility steam generating unit, the owner or operator shall submit a report to the Agency if the annual emissions, in tons per year, from the project identified in subsection (a), exceed the baseline actual emissions (as documented and maintained under subsection (a)(3)), by a significant amount (as defined in Section 203.1370) for that regulated NSR pollutant, and if such emissions differ from the preconstruction projection as documented and maintained under subsection (a)(3). Such report shall be submitted to the Agency within 60 days after the end of such year. The report shall contain the following:

 

1)         The name, address, and telephone number of the major stationary source;

 

2)         The annual emissions as calculated under subsection (c); and

 

3)         Any other information that the owner or operator wishes to include in the report (e.g., an explanation as to why the emissions differ from the preconstruction projection).

 

f)         A "reasonable possibility" under this Section occurs when the owner or operator calculates the project to result in either:

 

1)         A projected actual emissions increase of at least 50% of the amount that is a "significant emissions increase", as defined in Section 203.1380 (without reference to the amount that is a significant net emissions increase), for the regulated NSR pollutant; or

 

2)         A projected actual emissions increase that, added to the amount of emissions excluded under Section 203.1320(b)(3), sums to at least 50% of the amount that is a "significant emissions increase", as defined under Section 203.1380 (without reference to the amount that is a significant net emissions increase), for the regulated NSR pollutant. For a project for which a reasonable possibility occurs only within the meaning of this subsection (f)(2), and not also within the meaning of subsection (f)(1), then subsections (b) through (e) do not apply to the project.

 

g)         The owner or operator of the source shall make the information required to be documented and maintained pursuant to this Section available for review upon a request for inspection by the Agency or the USEPA or the general public pursuant to the requirements of Section 39.5(8)(e) of the Act.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1800  Lowest Achievable Emission Rate

 

a)         The owner or operator of a new major stationary source shall demonstrate that the control equipment and process measures applied to the source will produce LAER for each regulated NSR pollutant for which the stationary source is major.

 

b)         Except as provided in subsections (d) or (e), the owner or operator of a major modification shall demonstrate that the control equipment and process measures applied to the major modification will produce LAER for each regulated NSR pollutant for which the modification is major.  This requirement applies to each emissions unit at which a net increase in emissions of the regulated NSR pollutant has occurred or would occur as a result of a physical change or change in the method of operation in the emissions unit.

 

c)         The owner or operator shall provide a detailed showing that the proposed emission limitations constitute LAER.  Such demonstration shall include:

 

1)         A description of the manner in which the proposed emission limitation was selected, including a detailed listing of information resources,

 

2)         Alternative emission limitations, and

 

3)         Such other reasonable information as the Agency may request as necessary to determine whether the proposed emission limitation is LAER.

 

d)         If the owner or operator of a major stationary source (other than a source which emits or has the potential to emit 100 tpy or more of VOM or NO_X) located in an area classified as serious or severe nonattainment for ozone does not elect to provide internal offsets for a change at the source in accordance with Section 203.1220(d), such change shall be considered a major modification for purposes of this Part, but in applying this Section in the case of any such modification, the BACT, as defined in section 169 of the CAA (42 U.S.C. 7479), shall be substituted for the LAER.  BACT shall be determined in accordance with policies and procedures published by the USEPA.

 

e)         In the case of any major stationary source of VOM or NO_X located in an area classified as serious or severe nonattainment for ozone which emits or has the potential to emit 100 tpy or more of VOM or NO_X, respectively, whenever any change at that source results in a significant increase in emissions of VOM or NO_X, respectively, from any discrete operation, unit, or other pollutant emitting activity at the source, such increase shall be considered a major modification for purposes of this Part, except that if the owner or operator elects to offset the increase by a greater reduction in emissions of VOM or NO_X, respectively, from other operations, units or activities within the source at an internal offset ratio of at least 1.3 to 1, the requirements of this Section concerning LAER shall not apply.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1810  Emissions Offsets

 

a)         The general requirements for emissions offsets are:

 

1)         The owner or operator of a new major stationary source or major modification shall provide emissions offsets equal to or greater than the allowable emissions from the source or the increase in emissions from the modification sufficient to allow the Agency to determine that the source or modification will not interfere with reasonable further progress as set forth in section 173 of the CAA (42 U.S.C. 7503). 

 

A)        Emissions offsets are required for the following pollutants for which the area is designated nonattainment or precursors to such pollutant as follows:

 

i)          For a new major stationary source, each regulated NSR pollutant for which the stationary source is major.

 

ii)         For a major modification, each regulated NSR pollutant for which the modification is major.

 

B)        The total tonnage of increased emissions, in tpy, resulting from a major modification that must be offset shall be determined by summing the difference between the allowable emissions after the modification, as defined under Section 203.1050, and the actual emissions before the modification, as defined under Section 203.1040, for each emissions unit.

 

C)        The Agency shall allow the use of all or some portion of the available growth margin to satisfy this subsection if the owner or operator can present evidence that the possible sources of emissions offsets were investigated, none were available at that time and the new or modified major stationary source is located in a zone (within the nonattainment area) identified by the USEPA, in consultation with the Secretary of Housing and Urban Development, as a zone to which economic development should be targeted.

 

b)         The ratios for emissions offsets in ozone nonattainment areas are:

 

1)         For new major stationary sources or major modifications in ozone nonattainment areas, the ratio of total emissions reductions provided by emission offsets for VOM or NO_X to total increased emissions of such pollutants shall be at least as follows:

 

A)        1.1 to 1 in areas classified as marginal;

 

B)        1.15 to 1 in areas classified as moderate;

 

C)        1.2 to 1 in areas classified as serious;

 

D)        1.3 to 1 in areas classified as severe; and

 

E)        1.5 to 1 in areas classified as extreme.

 

2)         The offset requirement provided in subsection (b)(1)(E) shall not be applicable in extreme areas to a modification of an existing stationary source:

 

A)        If such modification consists of installation of equipment required to comply with the SIP or the CAA; or

 

B)        If the owner or operator of the stationary source elects to offset the increase by a greater reduction in emissions of such pollutant from other discrete operations, units, or activities within the source at an internal offset ratio of at least 1.3 to 1.

 

c)         The enforceability requirements for emissions offsets are:

 

1)         All emissions reductions relied upon as emissions offsets shall be federally enforceable.

 

2)         Except as provided in this subsection, emissions offsets shall be enforceable by the Agency and under the CAA.  If emissions reductions are to be obtained in a state that neighbors Illinois, the emissions reductions committed to shall be enforceable by the neighboring state and/or local agencies and under the CAA.

 

3)         Except as provided in this subsection, emissions offsets shall be accomplished prior to initial start-up of the new major stationary source or major modification.  Where the new major stationary source or the major modification is a replacement for an existing stationary source or emissions unit that is being shut down in order to provide necessary offsets, the Agency shall allow up to 180 days for shakedown of the new major stationary source or major modification before the existing stationary source or emissions unit is required to cease operation. 

 

d)         Sources providing emissions reductions to meet the requirements of this Section shall meet the following location requirements. 

 

1)         The emissions reductions shall be achieved in the same nonattainment area as the increase being offset, except as provided in subsection (d)(2).

 

2)         An owner or operator may obtain the necessary emissions reductions from another nonattainment area where such other area has an equal or higher nonattainment classification than the area in which the new or modified major stationary source is located and the emissions from such other area contribute to a violation of the NAAQS in the nonattainment area in which the new or modified major stationary source is located.

 

e)         Pollutants for emission offsets shall be determined as follows:

 

1)         Emission reductions shall be for the pollutant for which emission offsets are required, e.g., reductions in CO emissions cannot be used as emission offsets for increases in emissions of SO₂ reductions.

 

2)         Replacement of one VOM with another of lesser reactivity does not constitute an emissions reduction.

 

f)         Emissions reductions from shutdowns or curtailments shall be credited as follows:

 

1)         Emissions reductions achieved by shutting down an existing emissions unit or curtailing production or operating hours shall be credited for offsets if they meet the following requirements:

 

A)        Such reductions are surplus, permanent, quantifiable and federally enforceable; and

 

B)        The shutdown or curtailment occurred after the last day of the base year for the SIP planning process.  For this Subpart, the Agency shall consider a prior shutdown or curtailment to have occurred after the last day of the base year if the projected emissions inventory used to develop the attainment demonstration explicitly includes the emissions from such previously shutdown or curtailed emissions units.  However, in no event may credit be given for shutdowns that occurred before August 7, 1977.

 

2)         Emissions reductions achieved by shutting down an existing emissions unit or curtailing production or operating hours and that do not meet the requirements in subsection (f)(1)(B) shall be credited only if:

 

A)        The shutdown or curtailment occurred on or after the date the application for a construction permit is filed; or

 

B)        The applicant can establish that the proposed new emissions unit is a replacement for the shutdown or curtailed emissions unit, and the emissions reductions achieved by the shutdown or curtailment met the requirements of subsection (f)(1)(A).

 

g)         The determination of emissions reductions for offsets shall be made as follows:

 

1)         Credit for emissions reductions used as offsets shall be determined as follows:

 

A)        The baseline for determining credit for emissions reductions is the emissions limit under the applicable SIP in effect at the time the application for a construction permit is filed, except that the offset baseline shall be the actual emissions of the source from which offset credit is obtained where:

 

i)          The demonstration of reasonable further progress and attainment of ambient air quality standards is based upon the actual emissions of sources located within the designated nonattainment area; or

 

ii)         The applicable SIP does not contain an emissions limitation for that source or source category.

 

B)        Where the emissions limit under the applicable SIP allows greater emissions than the potential to emit of the source, emissions offset credit will be allowed only for control below the potential to emit.

 

C)        For an existing fuel combustion source, credit shall be based on the allowable emissions under the applicable SIP for the type of fuel being burned at the time the application for a construction permit is filed.  If the emissions offset is to be produced by a switch to a cleaner fuel at some future date, offset credit shall be subject to the following limitations:

 

i)          Emissions offset credit based on the allowable (or actual) emissions for the fuels involved is allowed only if the permit is conditioned to require the use of a specified alternative control measure which would achieve the same degree of emissions reduction should the source switch back to a dirtier fuel at some later date.

 

ii)         Emissions offset credit shall be allowed only if the owner or operator provides evidence that long-term supplies of the cleaner fuel are available.

 

2)         Emissions reductions shall not be credited for offsets to the extent they have been previously relied on by the Agency in issuing any permit pursuant to 35 Ill. Adm. Code 201.142 or 201.143 or this Part or for demonstrating attainment or reasonable further progress.

 

3)         Emissions reductions otherwise required by the CAA (42 U.S.C. 7401 et seq.) shall not be creditable as emission reductions for purposes of any such offset requirement.  Incidental emission reductions which are not otherwise required by the CAA shall be creditable as emission reductions for such purposes if such emissions reductions meet the requirements of this Section.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1820  Compliance by Existing Sources

 

The owner or operator shall demonstrate that all major stationary sources which he or she owns or operates (or which are owned or operated by any entity controlling or controlled by, or under common control, with the owner or operator) in Illinois are in compliance, or on a schedule for compliance, with all applicable state and federal air pollution control requirements.  For purposes of this Section, a schedule for compliance shall be federally enforceable or contained in an order of the Board or a court decree.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1830  Analysis of Alternatives

 

The owner or operator shall demonstrate that benefits of the new major source or major modification significantly outweigh the environmental and social costs imposed as a result of its location, construction, or modification, based upon an analysis of alternative sites, sizes, production processes, and environmental control techniques for such proposed source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.1900  General Maintenance of Emission Offsets

 

No person shall cease to maintain emission offsets which were provided for a source or modification which is subject to this Part.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2000  Offsetting by Alternative or Innovative Means

 

A source may offset, by alternative or innovative means, emission increases from rocket engine and motor firing, and cleaning related to such firing, at an existing or modified major source that tests rocket engines or motors under the following conditions:

 

a)         Any modification proposed is solely for expanding the testing of rocket engines or motors at an existing source that is permitted to test such engines on November 15, 1990;

 

b)         The source demonstrates to the satisfaction of the Agency that it has used all reasonable means to obtain and utilize offsets, as determined on an annual basis, for the emissions increases beyond allowable levels, that all available offsets are being used, and that sufficient offsets are not available to the source;

 

c)         The source has obtained a written finding from the Department of Defense, Department of Transportation, National Aeronautics and Space Administration or other appropriate federal agency, that the testing of rocket motors or engines at the facility is required for a program essential to the national security; and

 

d)         The source will comply with an alternative measure, imposed by the Agency or Board, designed to offset any emission increases beyond permitted levels not directly offset by the source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2100  Applicability

 

a)         The Agency may approve the use of an actuals PAL for any existing major stationary source, except as provided in subsection (b), if the PAL meets the requirements in this Subpart. The term "PAL" shall mean "actuals PAL" throughout this Subpart.

 

b)         The Agency shall not allow an actuals PAL for VOM or NO_X for any major stationary source located in an extreme ozone nonattainment area.

 

c)         Any physical change in or change in the method of operation of a major stationary source that maintains its total source-wide emissions below the PAL level, meets the requirements in this Subpart, and complies with the PAL permit:

 

1)         Is not a major modification for the PAL pollutant;

 

2)         Does not have to be approved through the major NSR program; and

 

3)         Is not subject to the provisions in Section 203.1430 (restrictions on relaxing enforceable emission limitations that the major stationary source used to avoid applicability of the major NSR program).

 

d)         Except as provided under subsection (c)(3), a major stationary source shall continue to comply with all applicable federal or State requirements, emission limitations, and work practice requirements that were established prior to the effective date of the PAL.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2110  Definitions

 

For this Subpart, the definitions in Section 203.2120 through Section 203.2290 apply. When a term is not defined in these Sections, it shall have the meaning given in Subpart I of this Part, Part 211, or in the CAA.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2120  Actuals PAL

 

"Actuals PAL" for a major stationary source means a PAL based on the baseline actual emissions (as defined in Section 203.1070) of all emissions units (as defined in Section 203.1160) at the source, that emit or have the potential to emit the PAL pollutant. 

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2130  Allowable Emissions

 

"Allowable emissions" means "allowable emissions" as defined in Section 203.1050, except that the allowable emissions for any emissions unit shall be calculated considering any emission limitations that are enforceable as a practical matter on the emissions unit's potential to emit.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2140  Best Available Control Technology (BACT)

 

"Best available control technology" or "BACT" means an emissions limitation (including a visible emissions standard) based on the maximum degree of reduction for each regulated NSR pollutant that would be emitted from any proposed major stationary source or major modification that the Agency, on a case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, determines is achievable for such source or modification through application of production processes or available methods, systems, and techniques, including fuel cleaning or treatment or innovative fuel combustion techniques for control of such pollutant.  In no event shall application of BACT result in emissions of any pollutant that would exceed the emissions allowed by any applicable standard under 40 CFR Parts 60, 61, 62, or 63 (as incorporated by reference in Section 203.1000).  If the Agency determines that technological or economic limitations on the application of measurement methodology to a particular emissions unit would make the imposition of an emissions standard infeasible, a design, equipment, work practice, operational standard, or combination thereof, may be prescribed instead to satisfy the requirement for the application of BACT.  Such standard shall, to the degree possible, set forth the emissions reduction achievable by implementation of such design, equipment, work practice or operation, and shall provide for compliance by means which achieve equivalent results.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2150  Continuous Emissions Monitoring System (CEMS)

 

"Continuous emissions monitoring system" or "CEMS" means all of the equipment that may be required to meet the data acquisition and availability requirements of this Subpart, to sample, condition (if applicable), analyze, and provide a record of emissions on a continuous basis.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2160  Continuous Emissions Rate Monitoring System (CERMS)

 

"Continuous emissions rate monitoring system" or "CERMS" means the total equipment required for the determination and recording of the pollutant mass emissions rate (in terms of mass per unit of time).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2170  Continuous Parameter Monitoring System (CPMS)

 

"Continuous parameter monitoring system" or "CPMS" means all of the equipment necessary to meet the data acquisition and availability requirements of this Subpart to monitor process and control device operational parameters (for example, control device secondary voltages and electric currents) and other information (for example, gas flow rate, O₂ or CO₂ concentrations), and to record average operational parameter value or values on a continuous basis.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2180  Federal Land Manager

 

"Federal Land Manager" means, with respect to any lands in the United States, the Secretary of the department with authority over the lands.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2190  Major Emissions Unit

 

"Major emissions unit" means:

 

a)         Any emissions unit that emits or has the potential to emit 100 tpy or more of the PAL pollutant in an attainment area; or

 

b)         Any emissions unit that emits or has the potential to emit the PAL pollutant in an amount that is equal to or greater than the major source threshold for the PAL pollutant as defined by the CAA for nonattainment areas.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2200  Plantwide Applicability Limitation (PAL)

 

"Plantwide applicability limitation" or ("PAL") means an emission limitation expressed in tons per year, for a pollutant at a major stationary source, that is enforceable as a practical matter and established source-wide in compliance with this Subpart.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2210  PAL Effective Date

 

"PAL effective date" generally means the date of issuance of the PAL permit. However, the PAL effective date for an increased PAL is the date any emissions unit that is part of the PAL major modification becomes operational and begins to emit the PAL pollutant.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2220  PAL Effective Period

 

"PAL effective period" means the period beginning with the PAL effective date and ending 10 years later.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2230  PAL Major Modification

 

"PAL major modification" means, notwithstanding Section 203.1220 and Section 203.1260 (the definitions for major modification and net emissions increase), any physical change in or change in the method of operation of the PAL source that causes it to emit the PAL pollutant at a level equal to or greater than the PAL.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2240  PAL Permit

 

"PAL permit" means the major NSR permit, the minor NSR permit, or the State operating permit under a program that is approved into the SIP, or the CAAPP permit issued by the Agency that establishes a PAL for a major stationary source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2250  PAL Pollutant

 

"PAL pollutant" means the pollutant for which a PAL is established at a major stationary source.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2260  Predictive Emissions Monitoring System (PEMS)

 

"Predictive emissions monitoring system" or "PEMS" means all of the equipment necessary to monitor process and control device operational parameters (for example, control device secondary voltages and electric currents) and other information (for example, gas flow rate, O₂ or CO₂ concentrations), and calculate and record the mass emissions rate (for example, pounds per hour) on a continuous basis.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2270  Reasonably Available Control Technology (RACT)

 

"Reasonably Available Control Technology" or "RACT" means devices, systems, process modifications, or other apparatus or techniques that are reasonably available taking into account:

 

a)         The necessity of imposing such controls in order to attain and maintain a national ambient air quality standard;

 

b)         The social, environmental, and economic impact of such controls; and

 

c)         Alternative means of providing for attainment and maintenance of such standard.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2280  Significant Emissions Unit

 

"Significant emissions unit" means an emissions unit that emits or has the potential to emit a PAL pollutant in an amount that is equal to or greater than the applicable significant level (as defined in Section 203.1370 or in the CAA, whichever is lower) for that PAL pollutant, but less than the amount that would qualify the unit as a major emissions unit as defined in Section 203.2190. 

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2290  Small Emissions Unit

 

"Small emissions unit" means an emissions unit that emits or has the potential to emit the PAL pollutant in an amount less than the significant level for that PAL pollutant, as defined in Section 203.1370 or in the CAA, whichever is lower.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2300  Permit Application Requirements

 

As part of a permit application requesting a PAL, the owner or operator of a major stationary source shall submit the following information to the Agency for approval:

 

a)         A list of all emissions units at the source designated as small, significant or major based on their potential to emit. In addition, the owner or operator of the source shall indicate which, if any, federal or State applicable requirements, emission limitations, or work practices apply to each unit.

 

b)         Calculations of the baseline actual emissions (with supporting documentation). Baseline actual emissions are to include emissions associated not only with operation of the unit, but also emissions associated with startup, shutdown, and malfunction.

 

c)         The calculation procedures that the major stationary source owner or operator proposes to use to convert the monitoring system data to monthly emissions and annual emissions based on a 12-month rolling total for each month as required by Section 203.2400(a).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2310  General Requirements for Establishing PAL

 

a)         The Agency is allowed to establish a PAL at a major stationary source provided that, at a minimum, the requirements of this Section are met.

 

1)         The PAL shall impose an annual emission limitation expressed on a mass basis in tons per year, that is enforceable as a practical matter, for the entire major stationary source. For each month during the PAL effective period after the first 12 months of establishing a PAL, the major stationary source owner or operator shall show that the sum of the monthly emissions from each emissions unit under the PAL for the previous 12 consecutive months is less than the PAL (a 12-month total, rolled monthly). For each month during the first 11 months from the PAL effective date, the major stationary source owner or operator shall show that the sum of the preceding monthly emissions from the PAL effective date for each emissions unit under the PAL is less than the PAL.

 

2)         The PAL shall be established in a PAL permit that meets the public participation requirements in Section 203.2320.

 

3)         The PAL permit shall contain all the requirements of Section 203.2340.

 

4)         The PAL shall include fugitive emissions, to the extent quantifiable, from all emissions units that emit or have the potential to emit the PAL pollutant at the major stationary source.

 

5)         Each PAL shall regulate emissions of only one pollutant.

 

6)         Each PAL shall have a PAL effective period of 10 years.

 

7)         The owner or operator of the major stationary source with a PAL shall comply with the monitoring, recordkeeping, and reporting requirements provided in Section 203.2390 through Section 203.2410 for each emissions unit under the PAL through the PAL effective period.

 

b)         At no time (during or after the PAL effective period) are emissions reductions of a PAL pollutant that occur during the PAL effective period creditable as decreases for purposes of offsets under Section 203.1810 unless the level of the PAL is reduced by the amount of those emissions reductions and such reductions would be creditable in the absence of the PAL.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2320  Public Participation Requirements

 

PALs for existing major stationary sources shall be established, renewed, or increased through a procedure that is consistent with 35 Ill. Adm. Code 252. This includes the requirement that the Agency provide the public with notice of the proposed approval of a PAL permit and at least a 30-day period for submittal of public comment. The Agency must address all material comments before taking final action on the permit.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2330  Setting the 10-Year Actuals PAL Level

 

a)         Except as provided in subsection (b), the actuals PAL level for a major stationary source shall be established as the sum of the baseline actual emissions (as defined in Section 203.1070) of the PAL pollutant for each emissions unit at the stationary source, plus an amount equal to the applicable significant level for the PAL pollutant under Section 203.1370 or under the CAA, whichever is lower. When establishing the actuals PAL level, for a PAL pollutant, only one consecutive 24-month period must be used to determine the baseline actual emissions for all existing emissions units. However, a different consecutive 24-month period may be used for each different PAL pollutant. Emissions associated with units that were permanently shut down after this 24-month period must be subtracted from the PAL level. The Agency shall specify a reduced PAL level or levels in tons per year in the PAL permit to become effective on the future compliance date or dates of any applicable federal or State regulatory requirement or requirements that the Agency is aware of prior to issuance of the PAL permit. For instance, if the source owner or operator will be required to reduce emissions from industrial boilers in half from baseline emissions of 60 parts per million NO_X to a new rule limit of 30 parts per million, then the permit shall contain a future effective PAL level that is equal to the current PAL level reduced by half of the original baseline actual emissions of such unit or units.

 

b)         For newly constructed units (which do not include modifications to existing units) on which actual construction began after the 24-month period, in lieu of adding the baseline actual emissions as specified in subsection (a), the emissions must be added to the PAL level in an amount equal to the potential to emit of the units.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2340  Contents of the PAL Permit

 

The PAL permit shall contain, at a minimum:

 

a)         The PAL pollutant and the applicable source-wide emission limitation in tons per year.

 

b)         The PAL permit effective date and the expiration date of the PAL (PAL effective period).

 

c)         Specification in the PAL permit that if a major stationary source owner or operator applies to renew a PAL in compliance with Section 203.2370 before the end of the PAL effective period, then the PAL shall not expire at the end of the PAL effective period. It shall remain in effect until a revised PAL permit is issued by the Agency.

 

d)         A requirement that emission calculations for compliance purposes must include emissions from startups, shutdowns, and malfunctions.

 

e)         A requirement that, once the PAL expires, the major stationary source is subject to the requirements of Section 203.2360.

 

f)         The calculation procedures that the major stationary source owner or operator shall use to convert the monitoring system data to monthly emissions and annual emissions based on a 12-month rolling total as required by Section 203.2400(a).

 

g)         A requirement that the major stationary source owner or operator monitor all emissions units in compliance with the provisions under Section 203.2390.

 

h)         A requirement to retain the records required under Section 203.2400 on site. Such records may be retained in an electronic format.

 

i)          A requirement to submit the reports required under Section 203.2410 by the required deadlines.

 

j)          Any other requirements that the Agency considers necessary to implement and enforce the PAL.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2350  Effective Period and Reopening a PAL Permit

 

The requirements in subsections (a) and (b) apply to actuals PALs.

 

a)         PAL effective period.  The Agency shall specify a PAL effective period of 10 years.

 

b)         Reopening of the PAL permit.

 

1)         During the PAL effective period, the Agency shall reopen the PAL permit to:

 

A)        Correct typographical/calculation errors made in setting the PAL or reflect a more accurate determination of emissions used to establish the PAL;

 

B)        Reduce the PAL if the owner or operator of the major stationary source creates creditable emissions reductions for use as emissions offsets under Section 203.1810; or

 

C)        Revise the PAL to reflect an increase in the PAL as provided under Section 203.2380.

 

2)         The Agency shall have discretion to reopen the PAL permit for the following:

 

A)        Reduce the PAL to reflect newly applicable federal requirements (for example, NSPS) with compliance dates after the PAL effective date;

 

B)        Reduce the PAL consistent with any other requirement, that is enforceable as a practical matter, and that the Agency may impose on the major stationary source under the SIP; or

 

C)        Reduce the PAL if the Agency determines that a reduction is necessary to avoid causing or contributing to a NAAQS or PSD increment violation, or to an adverse impact on an air quality related value that has been identified for a Federal Class I area by a Federal Land Manager and for which information is available to the general public.

 

c)         Except for the permit reopening in subsection (b)(1)(A) for the correction of typographical/calculation errors that do not increase the PAL level, all other reopenings shall be carried out in compliance with the public participation requirements of Section 203.2320.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2360  Expiration of a PAL

 

Any PAL that is not renewed in accordance with the procedures in Section 203.2370 shall expire at the end of the PAL effective period, and the requirements in this Section shall apply.

 

a)         Each emissions unit (or each group of emissions units) that existed under the PAL shall comply with an allowable emission limitation under a revised permit established according to the procedures in subsections (a)(1) and (2).

 

1)         Within the time frame specified for PAL renewals in Section 203.2370(b), the major stationary source shall submit a proposed allowable emission limitation for each emissions unit (or each group of emissions units, if such a distribution is more appropriate as decided by the Agency) by distributing the PAL allowable emissions for the major stationary source among each of the emissions units that existed under the PAL. If the PAL had not yet been adjusted for an applicable requirement that became effective during the PAL effective period, as required under Section 203.2370(e), such distribution shall be made as if the PAL had been adjusted.

 

2)         The Agency shall decide whether and how the PAL allowable emissions will be distributed and issue a revised permit incorporating allowable limits for each emissions unit, or each group of emissions units, as the Agency determines is appropriate.

 

b)         Each emissions unit or units shall comply with the allowable emission limitation on a 12-month rolling basis. The Agency may approve the use of monitoring systems (source testing, emission factors, etc.) other than CEMS, CERMS, PEMS, or CPMS to demonstrate compliance with the allowable emission limitation.

 

c)         Until the Agency issues the revised permit incorporating allowable limits for each emissions unit, or each group of emissions units, as required under subsection (a)(2), the source shall continue to comply with a source-wide, multi-unit emissions cap equivalent to the level of the PAL emission limitation.

 

d)         Any physical change or change in the method of operation at the major stationary source will be subject to major NSR requirements if such change meets the definition of major modification in Section 203.1220.

 

e)         The major stationary source owner or operator shall continue to comply with any State or federal applicable requirements (BACT, RACT, NSPS, etc.) that may have applied either during the PAL effective period or prior to the PAL effective period except for those emission limitations that had been established under Section 203.1420, but were eliminated by the PAL in compliance with the provisions in Section 203.2100(c)(3).

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2370  Renewal of a PAL

 

a)         The Agency shall follow the procedures specified in Section 203.2320 in approving any request to renew a PAL for a major stationary source, and shall provide both the proposed PAL level and a written rationale for the proposed PAL level to the public for review and comment. During such public review, any person may propose a PAL level for the source for consideration by the Agency.

 

b)         Application deadline.  A major stationary source owner or operator shall submit a timely application to the Agency to request renewal of a PAL. A timely application is one that is submitted at least 6 months prior to, but not earlier than 18 months from, the date of permit expiration. This deadline for application submittal is to ensure that the permit will not expire before the permit is renewed. If the owner or operator of a major stationary source submits a complete application to renew the PAL within this time period, then the PAL shall continue to be effective until the revised permit with the renewed PAL is issued.

 

c)         Application requirements.  The application to renew a PAL permit shall contain:

 

1)         The information required in Section 203.2300(a) through (c).

 

2)         A proposed PAL level.

 

3)         The sum of the potential to emit of all emissions units under the PAL (with supporting documentation).

 

4)         Any other information the owner or operator wishes the Agency to consider in determining the appropriate level for renewing the PAL.

 

d)         PAL adjustment.  In determining whether and how to adjust the PAL, the Agency shall consider the options outlined in subsections (d)(1) and (2). However, in no case may any such adjustment fail to comply with subsection (d)(3).

 

1)         If the emissions level calculated in compliance with Section 203.2330 is equal to or greater than 80% of the PAL level, the Agency may renew the PAL at the same level without considering the factors set forth in subsection (d)(2); or

 

2)         The Agency may set the PAL at a level that it determines to be more representative of the stationary source's baseline actual emissions, or that it determines to be more appropriate considering air quality needs, advances in control technology, anticipated economic growth in the area, desire to reward or encourage the source's voluntary emissions reductions, or other factors as specifically identified by the Agency in its written rationale.

 

3)         Notwithstanding subsections (d)(1) and (2):

 

A)        If the potential to emit of the major stationary source is less than the PAL, the Agency shall adjust the PAL to a level no greater than the potential to emit of the source; and

 

B)        The Agency shall not approve a renewed PAL level higher than the current PAL, unless the major stationary source has complied with the provisions of Section 203.2380 (increasing a PAL).

 

e)         If the compliance date for a State or federal requirement that applies to the PAL source occurs during the PAL effective period, and if the Agency has not already adjusted for such requirement, the PAL shall be adjusted at the time of PAL permit renewal or CAAPP permit renewal, whichever occurs first.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2380  Increasing the PAL During the PAL Effective Period

 

a)         The Agency may increase a PAL emission limitation only if the major stationary source complies with the provisions in subsections (a)(1) through (4).

 

1)         The owner or operator of the major stationary source shall submit a complete application to request an increase in the PAL limit for a PAL major modification. Such application shall identify the emissions unit or units contributing to the increase in emissions so as to cause the major stationary source's emissions to equal or exceed its PAL.

 

2)         As part of this application, the major stationary source owner or operator shall demonstrate that the sum of the baseline actual emissions of the small emissions units, plus the sum of the baseline actual emissions of the significant and major emissions units assuming application of BACT equivalent controls, plus the sum of the allowable emissions of the new or modified emissions unit or units exceeds the PAL. The level of control that would result from BACT equivalent controls on each significant or major emissions unit shall be determined by conducting a new BACT analysis at the time the application is submitted, unless the emissions unit is currently required to comply with a BACT or LAER requirement that was established within the preceding 10 years. In such a case, the assumed control level for that emissions unit shall be equal to the level of BACT or LAER with which that emissions unit must currently comply.

 

3)         The owner or operator obtains a major NSR permit for all emissions unit or units identified in subsection (a)(1), regardless of the magnitude of the emissions increase resulting from them (that is, no significant levels apply). These emissions unit or units shall comply with any emissions requirements resulting from the major NSR process (for example, LAER), even though they have also become subject to the PAL or continue to be subject to the PAL.

 

4)         The PAL permit shall require that the increased PAL level shall be effective on the day any emissions unit that is part of the PAL major modification becomes operational and begins to emit the PAL pollutant.

 

b)         The Agency shall calculate the new PAL as the sum of the allowable emissions for each modified or new emissions unit, plus the sum of the baseline actual emissions of the significant and major emissions units (assuming application of BACT equivalent controls as determined in accordance with subsection (a)(2)), plus the sum of the baseline actual emissions of the small emissions units.

 

c)         The PAL permit shall be revised to reflect the increased PAL level under the public notice requirements of Section 203.2320.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2390  Monitoring Requirements

 

a)         General requirements.

 

1)         Each PAL permit must contain enforceable requirements for the monitoring system that accurately determines plantwide emissions of the PAL pollutant in terms of mass per unit of time. Any monitoring system authorized for use in the PAL permit must be based on sound science and meet generally acceptable scientific procedures for data quality and manipulation. Additionally, the information generated by such system must meet minimum legal requirements for admissibility in a judicial proceeding to enforce the PAL permit.

 

2)         The PAL monitoring system must employ one or more of the four general monitoring approaches meeting the performance requirements in subsection (b)(1) through (4) and must be approved by the Agency.

 

3)         Notwithstanding subsection (a)(2), the owner or operator may also employ an alternative monitoring approach that meets subsection (a)(1) if approved by the Agency.

 

4)         Failure to use a monitoring system that meets the requirements of this Section renders the PAL invalid.

 

b)         Minimum Performance Requirements for Approved Monitoring Approaches. The following are acceptable general monitoring approaches when conducted in compliance with the requirements in subsections (c) through (i):

 

1)         Mass balance calculations for activities using coatings or solvents;

 

2)         CEMS;

 

3)         CPMS or PEMS; and

 

4)         Emission factors.

 

c)         Mass Balance Calculations.  An owner or operator using mass balance calculations to monitor PAL pollutant emissions from activities using coating or solvents shall meet the following requirements:

 

1)         Provide a demonstrated means of validating the published content of the PAL pollutant that is contained in or created by all materials used in or at the emissions unit;

 

2)         Assume that the emissions unit emits all of the PAL pollutant that is contained in or created by any raw material or fuel used in or at the emissions unit, if it cannot otherwise be accounted for in the process; and

 

3)         Where the vendor of a material or fuel, which is used in or at the emissions unit, publishes a range of pollutant content from such material, the owner or operator must use the highest value of the range to calculate the PAL pollutant emissions unless the Agency determines there is site-specific data or a site-specific monitoring program to support another content within the range.

 

d)         CEMS.  An owner or operator using CEMS to monitor PAL pollutant emissions shall meet the following requirements:

 

1)         CEMS must comply with applicable Performance Specifications found in 40 CFR Part 60, Appendix B (incorporated by reference in Section 203.1000); and

 

2)         CEMS must sample, analyze and record data at least every 15 minutes while the emissions unit is operating.

 

e)         CPMS or PEMS.  An owner or operator using CPMS or PEMS to monitor PAL pollutant emissions shall meet the following requirements:

 

1)         The CPMS or the PEMS must be based on current site-specific data demonstrating a correlation between the monitored parameter or parameters and the PAL pollutant emissions across the range of operation of the emissions unit; and

 

2)         Each CPMS or PEMS must sample, analyze, and record data at least every 15 minutes, or at another less frequent interval approved by the Agency, while the emissions unit is operating.

 

f)         Emission Factors.  An owner or operator using emission factors to monitor PAL pollutant emissions shall meet the following requirements:

 

1)         All emission factors shall be adjusted, if appropriate, to account for the degree of uncertainty or limitations in the factors' development;

 

2)         The emissions unit shall operate within the designated range of use for the emission factor, if applicable; and

 

3)         If technically practicable, the owner or operator of a significant emissions unit that relies on an emission factor to calculate PAL pollutant emissions shall conduct validation testing to determine a site-specific emission factor within 6 months of PAL permit issuance, unless the Agency determines that testing is not required.

 

g)         A source owner or operator must record and report maximum potential emissions without considering enforceable emission limitations or operational restrictions for an emissions unit during any period of time that there is no monitoring data, unless another method for determining emissions during such periods is specified in the PAL permit.

 

h)         Notwithstanding the requirements in subsections (c) through (g), where an owner or operator of an emissions unit cannot demonstrate a correlation between the monitored parameter or parameters and the PAL pollutant emissions rate at all operating points of the emissions unit, the Agency shall, at the time of permit issuance:

 

1)         Establish default value or values for determining compliance with the PAL based on the highest potential emissions reasonably estimated at such operating point or operating points; or

 

2)         Determine that operation of the emissions unit during operating conditions when there is no correlation between monitored parameter or parameters and the PAL pollutant emissions is a violation of the PAL.

 

i)          Re-validation.  All data used to establish the PAL pollutant must be re-validated through performance testing or other scientifically valid means approved by the Agency. The testing must occur at least once every 5 years after issuance of the PAL.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2400  Recordkeeping Requirements

 

a)         The PAL permit shall require an owner or operator to retain a copy of all records necessary to determine compliance with any requirement of this Subpart and of the PAL, including a determination of each emissions unit's 12-month rolling total emissions, for 5 years from the date of such record.

 

b)         The PAL permit shall require an owner or operator to retain a copy of the following records for the duration of the PAL effective period plus 5 years:

 

1)         A copy of the PAL permit application and any applications for revisions to the PAL; and

 

2)         Each annual certification of compliance under Section 39.5(7)(p)(v) of the Act and the data relied on in certifying the compliance.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2410  Reporting and Notification Requirements

 

The owner or operator shall submit semi-annual monitoring reports and prompt deviation reports to the Agency in accordance with the CAAPP. The reports shall meet the requirements in subsections (a) through (c).

 

a)         Semi-annual report.  The semi-annual report shall be submitted to the Agency within 30 days after the end of each reporting period. This report shall contain the information required in subsections (a)(1) through (7).

 

1)         Identification of owner and operator and the permit number.

 

2)         Total annual emissions (tons/year) based on a 12-month rolling total for each month in the reporting period recorded pursuant to Section 203.2400(a).

 

3)         All data relied upon, including any Quality Assurance or Quality Control data, in calculating the monthly and annual PAL pollutant emissions.

 

4)         A list of any emissions units modified or added to the major stationary source during the preceding 6-month period.

 

5)         The number, duration, and cause of any deviations or monitoring malfunctions (other than the time associated with zero and span calibration checks), and any corrective action taken.

 

6)         A notification of a shutdown of any monitoring system, whether the shutdown was permanent or temporary, the reason for the shutdown, the anticipated date that the monitoring system will be fully operational or replaced with another monitoring system, and whether the emissions unit monitored by the monitoring system continued to operate, and the calculation of the emissions of the pollutant or the number determined by method included in the permit, as provided by Section 203.2390(g).

 

7)         A signed statement by the responsible official (as defined by the CAAPP) certifying the truth, accuracy, and completeness of the information provided in the report.

 

b)         Deviation report.  The major stationary source owner or operator shall promptly submit reports of any deviations or exceedance of the PAL requirements, including periods where no monitoring is available. A report submitted pursuant to 40 CFR 70.6(a)(3)(iii)(B) shall satisfy this reporting requirement. The deviation reports shall be submitted within the time limits prescribed by the applicable program implementing 40 CFR 70.6(a)(3)(iii)(B). The reports shall contain the following information:

 

1)         The identification of owner and operator and the permit number;

 

2)         The PAL requirement that experienced the deviation or that was exceeded;

 

3)         Emissions resulting from the deviation or the exceedance; and

 

4)         A signed statement by the responsible official (as defined by the CAAPP) certifying the truth, accuracy, and completeness of the information provided in the report.

 

c)         Re-validation results.  The owner or operator shall submit to the Agency the results of any re-validation test or method within 3 months after completion of such test or method.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2420  Transition Requirements

 

The Agency may not issue a PAL that does not comply with the requirements in this Subpart.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2500  Applicability

 

a)         In any area designated as attainment or unclassifiable under sections 107(d)(l)(A)(ii) or (iii) of the CAA (42 U.S.C. 7407(d)(l)(A)(ii) or (iii)), no person shall begin actual construction of a new major stationary source or major modification if the emissions from the major stationary source or major modification would cause or contribute to a violation of any NAAQS, except as in compliance with this Subpart. 

 

b)         This Subpart shall not apply to a major stationary source or major modification with respect to a particular pollutant if the owner or operator demonstrates that, as to that pollutant, the source or modification is located in an area designated as nonattainment pursuant to section 107 of the CAA (42 U.S.C. 7407).

 

c)         The applicability of 35 Ill. Adm. Code 204 is not affected by the applicability of this Subpart.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2510  Criteria

 

For this Subpart, the emissions from a new major stationary source or major modification will be considered to cause or contribute to a violation of a NAAQS if such source or modification would exceed the following significance levels at any locality that does not or would not meet the applicable NAAQS.

 

Pollutant	Significant Level (μg/m3)
	Annual Average	24-hour Average	8-hour Average	3-hour Average	1-hour Average
SO2	1.0	5		25
PM10	1.0	5
PM2.5	0.3	1.2
NO2	1.0
CO			500		2,000

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2520  Requirements

 

If the owner or operator of the proposed major stationary source or major modification does not fulfill the requirements of both subsections (a) and (b), the Agency shall deny the proposed construction.

 

a)         The owner or operator shall reduce the impact of its emissions on air quality by obtaining sufficient emissions reductions to, at a minimum, compensate for its adverse ambient impact when the major stationary source or major modification would otherwise cause or contribute to a violation of a NAAQS; and

 

b)         The owner or operator shall comply with the requirements of Section 203.1410(c) and (e), Section 203.1420, Section 203.1430, Section 203.1440(a), Section 203.1460, and Section 203.1500.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)

 

Section 203.2530  Construction Permit

 

a)         The Agency shall only issue a construction permit for a new major stationary source or a major modification that is subject to the requirements of this Subpart if the Agency determines that the source meets all applicable requirements of this Subpart.

 

b)         The Agency shall include in any construction permit issued pursuant to this Subpart, conditions specifying the manner in which the applicable requirements of this Subpart are met.

 

c)         In issuing a permit under this Subpart, the Agency shall follow the public participation procedures of Section 203.1610 or 35 Ill. Adm. Code 204.1320 as applicable.

 

(Source:  Added at 49 Ill. Reg. 6237, effective April 23, 2025)