Section 204.100  Incorporations by Reference

 

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

 

a)         40 CFR Part 50 (2018)

 

b)         40 CFR Part 51 (2018)

 

c)         40 CFR Part 52 (2018)

 

d)         40 CFR Part 53 (2018)

 

e)         40 CFR Part 54 (2018)

 

f)         40 CFR Part 55 (2018)

 

g)         40 CFR Part 56 (2018)

 

h)         40 CFR Part 57 (2018)

 

i)          40 CFR Part 58 (2018)

 

j)          40 CFR Part 59 (2018)

 

k)         40 CFR Part 60 (2018)

 

l)          40 CFR Part 61 (2018)

 

m)        40 CFR Part 62 (2018)

 

n)         40 CFR Part 63 (2018)

 

o)         40 CFR Part 64 (2018)

 

p)         40 CFR Part 65 (2018)

 

q)         40 CFR Part 66 (2018)

 

r)          40 CFR Part 67 (2018)

 

s)         40 CFR Part 68 (2018)

 

t)          40 CFR Part 69 (2018)

 

u)         40 CFR Part 70 (2018)

 

v)         40 CFR Part 71 (2018)

 

w)        40 CFR Part 72 (2018)

 

x)         40 CFR Part 73 (2018)

 

y)         40 CFR Part 74 (2018)

 

z)         40 CFR Part 75 (2018)

 

aa)       40 CFR Part 76 (2018)

 

bb)       40 CFR Part 77 (2018)

 

cc)       40 CFR Part 78 (2018)

 

dd)      40 CFR Part 79 (2018)

 

ee)       40 CFR Part 80 (2018)

 

ff)        40 CFR Part 81 (2018)

 

gg)       40 CFR Part 82 (2018)

 

hh)       (Reserved)

 

ii)         (Reserved)

 

jj)         40 CFR Part 85 (2018)

 

kk)       40 CFR Part 86 (2018)

 

ll)         40 CFR Part 87 (2018)

 

mm)     40 CFR Part 88 (2018)

 

nn)       40 CFR Part 89 (2018)

 

oo)       40 CFR Part 90 (2018)

 

pp)       40 CFR Part 91 (2018)

 

qq)       40 CFR Part 92 (2018)

 

rr)        40 CFR Part 93 (2018)

 

ss)        40 CFR Part 94 (2018)

 

tt)        40 CFR Part 95 (2018)

 

uu)       40 CFR Part 96 (2018)

 

vv)       40 CFR Part 97 (2018), excluding 40 CFR Part 97, Subpart FFFFF (2018)

 

ww)     40 CFR Part 98 (2018)

 

xx)       (Reserved)

 

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

 

Section 204.110  Abbreviations and Acronyms

 

The following abbreviations, acronyms and terms 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

CO₂                             carbon dioxide

CO₂e                           carbon dioxide equivalent

CPMS                         Continuous Parameter Monitoring System

GHG                           Greenhouse Gas

H₂S                             hydrogen sulfide

hr                                 hour

LAER                         Lowest Achievable Emission Rate

lbs                                pounds

lb/hr                             pounds per hour

MW                             megawatts

NAAQS                      National Ambient Air Quality Standards

NAICS                        North American Industry Classification System

NO₂                             nitrogen dioxide

NO_x                             nitrogen oxides

NSPS                          New Source Performance Standards

NSR                            New Source Review

O₂                                oxygen

PAL                            Plantwide Applicability Limitation

PEMS                          Predictive Emissions Monitoring System

PM                              Particulate Matter

PM_2.5                           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

ppm                             parts per million

PSD                             Prevention of Significant Deterioration

RACT                         Reasonably Available Control Technology

SIP                              State Implementation Plan

SO₂                             sulfur dioxide

tpy                               tons per year

TSP                             total suspended particulates

US                               United States

USEPA                       United States Environmental Protection Agency

VOC                           Volatile Organic Compound

VOM                           Volatile Organic Material

yr                                 year

 

Section 204.120  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.

 

Section 204.200  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 211.

 

Section 204.210  Actual Emissions

 

a)         "Actual emissions" means the actual rate of emissions of a regulated NSR pollutant from an emissions unit, as determined in accordance with subsections (b) through (d), except that this definition shall not apply for calculating whether a significant emissions increase has occurred, or for establishing a PAL under Subpart K.  Instead, Sections 204.240 and 204.600 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 that precedes the particular date and that is representative of normal source operation.  The Agency shall allow the use of a different time period upon a determination that it is more 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.

 

c)         The Agency may presume that source-specific allowable emissions for the unit are equivalent to the actual emissions of the unit.

 

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

 

Section 204.220  Adverse Impact on Visibility

 

"Adverse impact on visibility" means visibility impairment that interferes with the management, protection, preservation or enjoyment of the visitor's visual experience of the Federal Class I area.  This determination must be made on a case-by-case basis taking into account the geographic extent, intensity, duration, frequency and time of visibility impairment, and how these factors correlate with:

 

a)         Times of visitor use of the Federal Class I area; and

 

b)         Frequency and timing of natural conditions that reduce visibility.

 

Section 204.230  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 that restrict the operating rate, or hours of operation, or both) and the most stringent of the following:

 

a)         The applicable standards as set forth in 40 CFR 60, 61, 62 and 63 (incorporated by reference in Section 204.100);

 

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.

 

Section 204.240  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 this Section.

 

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 reviewing authority for a permit required under 40 CFR 52.21 or 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 63 (incorporated by reference in Section 204.100), 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 40 CFR 51.165(a)(3)(ii)(G).

 

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 the 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).

 

Section 204.250  Baseline Area

 

a)         "Baseline area" means any intrastate area (and every part thereof) designated as attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the CAA (42 USC 7407(d)(1)(A)(ii) or (iii)) in which the major source or major modification establishing the minor source baseline date would construct or would have an air quality impact for the pollutant for which the baseline date is established, as follows: Equal to or greater than 1 μg/m³ (annual average) for SO₂, NO₂, or PM₁₀; or equal to or greater than 0.3 μg/m³ (annual average) for PM_2.5.

 

b)         Area redesignations under section 107(d)(1)(A)(ii) or (iii) of the CAA cannot intersect or be smaller than the area of impact of any major stationary source or major modification that:

 

1)         Establishes a minor source baseline date; or

 

2)         Is subject to this Part and would be constructed in the state proposing the redesignation.

 

c)         Any baseline area established originally for the TSP increments shall remain in effect and shall apply for purposes of determining the amount of available PM₁₀ increments, except that such baseline area shall not remain in effect if the Agency rescinds the corresponding minor source baseline date in accordance with Section 204.520(c).

 

Section 204.260  Baseline Concentration

 

a)         "Baseline concentration" means the ambient concentration level that exists in the baseline area at the time of the applicable minor source baseline date.  A baseline concentration is determined for each pollutant for which a minor source baseline date is established and shall include:

 

1)         The actual emissions, as defined in Section 204.210, representative of sources in existence on the applicable minor source baseline date, except as provided in subsection (b); and

 

2)         The allowable emissions of major stationary sources that commenced construction before the major source baseline date, but were not in operation by the applicable minor source baseline date.

 

b)         The following will not be included in the baseline concentration and will affect the applicable maximum allowable increase or increases:

 

1)         Actual emissions, as defined in Section 204.210, from any major stationary source on which construction commenced after the major source baseline date.  For a major stationary source in existence on the major source baseline date, "actual emissions" for the purposes of this subsection (b) means increases or decreases in actual emissions resulting from construction commencing after the major source baseline date; and

 

2)         Actual emissions increases and decreases, as defined in Section 204.210, at any stationary source occurring after the minor source baseline date.

 

Section 204.270  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 are not limited to, installation of building supports and foundations, laying 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 that mark the initiation of the change.

 

Section 204.280  Best Available Control Technology (BACT)

 

"Best Available Control Technology" means an emissions limitation (including a visible emission 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 60, 61, 62 and 63 (incorporated by reference in Section 204.100).  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 that achieve equivalent results.

 

Section 204.290  Building, Structure, Facility, or Installation

 

a)         "Building, structure, facility, or installation" means all of the pollutant-emitting activities that 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 204.100).

 

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, 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:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.300  Clean Coal Technology

 

"Clean coal technology" means any technology, including technologies applied at the precombustion, combustion, or postcombustion stage, at a new or existing facility that will achieve significant reductions in air emissions of SO₂ or NO_X associated with the utilization of coal in the generation of electricity, or process steam that was not in widespread use as of November 15, 1990.

 

Section 204.310  Clean Coal Technology Demonstration Project

 

"Clean coal technology demonstration project" means a project using funds appropriated under the heading "Department of Energy – Clean Coal Technology", up to a total amount of $2,500,000,000 for commercial demonstration of clean coal technology, or similar projects funded through appropriations to USEPA.  The federal contribution for a qualifying project shall be at least 20 percent of the total cost of the demonstration project.

 

Section 204.320  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, that 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.

 

Section 204.330  Complete

 

"Complete" means, in reference to an application for a permit, that the application contains all of the information necessary for processing the application.  Designating an application complete for purposes of permit processing does not preclude the reviewing authority from requesting or accepting any additional information.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.340  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.

 

Section 204.350  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 such 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.

 

Section 204.360  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.

 

Section 204.370  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 204.360.  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 the 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 204.620, is an existing emissions unit.

 

Section 204.380  Excessive Concentration

 

"Excessive concentration" is defined for the purpose of determining good engineering practice stack height under Section 204.420(a)(3) and means:

 

a)         For sources seeking credit for stack height exceeding that established under Section 204.420(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 percent 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 percent 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 Section 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 204.420(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 204.420(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 204.420(a)(2), a maximum ground-level concentration due in whole or part to downwash, wakes or eddy effects that is at least 40 percent in excess of the maximum concentration experienced in the absence of the downwash, wakes, or eddy effects.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.390  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.

 

Section 204.400  Federally Enforceable

 

"Federally enforceable" means all limitations and conditions that are enforceable by USEPA, including those requirements developed under 40 CFR 60, 61, 62 and 63 (incorporated by reference in Section 204.100), requirements within the SIP, any permit requirements established under 40 CFR 52.21 (incorporated by reference in Section 204.100) or this Part or under regulations approved under 40 CFR 51, subpart I (incorporated by reference in Section 204.100), including operating permits issued under a USEPA-approved program that is incorporated into the SIP and expressly requires adherence to any permit issued under such program.

 

Section 204.410  Fugitive Emissions

 

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

 

Section 204.420  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 51 and 52 (incorporated by reference in Section 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:

 

H_g = 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:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.430  Greenhouse Gases (GHGs)

 

"Greenhouse gases" or "GHGs" means the air pollutant defined in 40 CFR 86.1818-12(a) as the aggregate group of six greenhouse gases: CO₂, nitrous oxide, methane, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride.  To represent an amount of GHGs emitted, the term "tpy CO₂ equivalent emissions (CO₂e)" shall be used.  CO₂e is computed as follows:

 

a)         Multiply the mass amount of emissions (tpy), for each of the six greenhouse gases in the pollutant GHGs, by the gas' associated global warming potential published at 40 CFR 98, subpart A, table A-1 (Global Warming Potentials) (incorporated by reference in Section 204.100).

 

b)         Sum the resultant value for each gas to compute tpy CO₂e.

 

Section 204.440  High Terrain

 

"High terrain" means any area having an elevation 900 feet or more above the base of the stack of a source.

 

Section 204.450  Indian Reservation

 

"Indian reservation" means any federally recognized reservation established by treaty, agreement, executive order, or Act of Congress.

 

Section 204.460  Indian Governing Body

 

"Indian Governing Body" means the governing body of any tribe, band, or group of Indians subject to the jurisdiction of the U.S. and recognized by the U.S. as possessing power of self-government.

 

Section 204.470  Innovative Control Technology

 

"Innovative control technology" means any system of air pollution control that has not been adequately demonstrated in practice, but would have a substantial likelihood of achieving greater continuous emissions reduction than any control system in current practice or of achieving at least comparable reductions at lower cost in terms of energy, economics, or non-air quality environmental impacts.

 

Section 204.480  Low Terrain

 

"Low terrain" means any area other than high terrain.

 

Section 204.490  Major Modification

 

a)         "Major modification" means any physical change in or change in the method of operation of a major stationary source that would result in:

 

1)         A significant emissions increase (as defined in Section 204.670) of a regulated NSR pollutant (as defined in Section 204.610) other than GHGs (as defined in Section 204.430); and

 

2)         A significant net emissions increase of that pollutant from the major stationary source.

 

b)         Any significant emissions increase (as defined in Section 204.670) from any emissions units or net emissions increase (as defined in Section 204.550) 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 sections 2(a) and (b) of the Energy Supply and Environmental Coordination Act of 1974 (15 USC 791) (or any superseding legislation); or

 

B)        A natural gas curtailment plan under the Federal Power Act (16 USC 791);

 

3)         Use of an alternative fuel by reason of an order or rule under section 125 of the CAA (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)        The source was capable of accommodating before January 6, 1975, unless the change would be prohibited under any federally enforceable permit condition established after January 6, 1975 under 40 CFR 52.21, 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, 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 would be prohibited under any federally enforceable permit condition established after January 6, 1975, under 40 CFR 52.21, this Part, or 35 Ill. Adm. Code 201.142 or 201.143;

 

7)         Any change in ownership at a stationary source;

 

8)         The installation, operation, cessation, or removal of a temporary clean coal technology demonstration project, provided that the project complies with:

 

A)        The Illinois SIP; and

 

B)        Other requirements necessary to attain and maintain NAAQS during the project and after it is terminated; or

 

9)         The installation or operation of a permanent clean coal technology demonstration project that constitutes repowering, provided that the project does not result in an increase in the potential to emit of any regulated pollutant emitted by the unit.  This exemption shall apply on a pollutant-by-pollutant basis.

 

d)         This definition shall not apply with respect to a particular regulated NSR pollutant when the major stationary source is complying with Subpart K for a PAL for that pollutant. Instead, the definition at Section 204.1720 shall apply.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.500  Major Source Baseline Date

 

"Major source baseline date" means:

 

a)         In the case of PM₁₀ and SO₂, January 6, 1975;

 

b)         In the case of NO₂, February 8, 1988; and

 

c)         In the case of PM_2.5, October 20, 2010.

 

Section 204.510  Major Stationary Source

 

a)         "Major stationary source" means:

 

1)         Any of the following stationary sources of air pollutants that emits, or has the potential to emit, 100 tpy or more of any regulated NSR pollutant:

 

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

 

B)        Coal cleaning plants (with thermal dryers);

 

C)        Kraft pulp mills;

 

D)        Portland cement plants;

 

E)        Primary zinc smelters;

 

F)         Iron and steel mill plants;

 

G)        Primary aluminum ore reduction plants (with thermal dryers);

 

H)        Primary copper smelters;

 

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

 

J)         Hydrofluoric, sulfuric, and nitric acid plants;

 

K)        Petroleum refineries;

 

L)        Lime plants;

 

M)       Phosphate rock processing plants;

 

N)        Coke oven batteries;

 

O)        Sulfur recovery plants;

 

P)         Carbon black plants (furnace process);

 

Q)        Primary lead smelters;

 

R)        Fuel conversion plants;

 

S)         Sintering plants;

 

T)         Secondary metal production plants;

 

U)        Chemical process plants (which does not include ethanol production facilities that produce ethanol by natural fermentation included in NAICS Codes 325193 or 312140);

 

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

 

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

 

X)        Taconite ore processing plants;

 

Y)        Glass fiber processing plants; and

 

Z)        Charcoal production plants;

 

2)         Notwithstanding the stationary source size specified in subsection (a)(1), any stationary source that emits, or has the potential to emit, 250 tpy or more of a regulated NSR pollutant (except GHGs as defined in Section 204.430); or

 

3)         Any physical change that would occur at a stationary source not otherwise qualifying under this Section as a major stationary source, if the changes would constitute a major stationary source.

 

b)         A major source that is major for VOM or NO_X shall be considered major for ozone.

 

c)         The fugitive emissions of a stationary source shall not be included in determining for any of the purposes of this Part 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.  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 category that, as of August 7, 1980, is being regulated under section 111 or 112 of the CAA.

 

Section 204.520  Minor Source Baseline Date

 

a)         "Minor source baseline date" means the earliest date after the trigger date on which a major stationary source or a major modification subject to 40 CFR 52.21 or this Part submits a complete application under the relevant regulations.  The trigger date is:

 

1)         In the case of PM₁₀ and SO₂, August 7, 1977;

 

2)         In the case of NO₂, February 8, 1988; and

 

3)         In the case of PM_2.5, October 20, 2011.

 

b)         The baseline date is established for each pollutant for which increments or other equivalent measures have been established if:

 

1)         The area in which the proposed source or modification would construct is designated as attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the CAA (42 USC 7407(d)(1)(A)(ii) or (iii)) for the pollutant on the date of its complete application under 40 CFR 52.21 or this Part; and

 

2)         In the case of a major stationary source, the pollutant would be emitted in significant amounts or, in the case of a major modification, there would be a significant net emissions increase of the pollutant.

 

c)         Any minor source baseline date established originally for the TSP increments shall remain in effect and shall apply for purposes of determining the amount of available PM₁₀ increments, except that the Agency shall rescind a minor source baseline date when it can be shown, to the satisfaction of the Agency, that the emissions increase from the major stationary source, or net emissions increase from the major modification, responsible for triggering that date did not result in a significant amount of PM₁₀ emissions.

 

Section 204.530  Nearby

 

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

 

a)         For purposes of applying the formula provided in Section 204.420(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 204.420(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 204.420(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.

 

Section 204.540  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 that are part of the applicable SIP.

 

Section 204.550  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 under Section 204.800(d); 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 subsection (a)(2) shall be determined as provided in Section 204.240, except that Section 204.240(a)(3) and (b)(4) shall not apply.

 

b)         An increase or decrease in actual emissions is contemporaneous with the increase from the particular change only if it occurs between:

 

1)         The date five years before construction on the particular change commences; and

 

2)         The date that the increase from the particular change occurs.

 

3)         An increase or decrease in actual emissions is creditable only if the reviewing authority has not relied on it in issuing a permit for the source under 40 CFR 52.21 or this Part, which permit is in effect when the increase in actual emissions from the particular change occurs.

 

c)         An increase or decrease in actual emissions of SO₂, PM, or NO_X that occurs before the applicable minor source baseline date is creditable only if it is required to be considered in calculating the amount of maximum allowable increases remaining available.

 

d)         An increase in actual emissions is creditable only to the extent that the new level of actual emissions exceeds the old level.

 

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

 

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

 

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

 

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

 

f)         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 emissions unit that replaces an existing emissions unit that requires shakedown becomes operational only after a reasonable shakedown period, not to exceed 180 days.

 

g)         Section 204.210(b) shall not apply in determining creditable increases and decreases.

 

Section 204.560  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 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.

 

Section 204.570  Prevention of Significant Deterioration (PSD) Permit

 

"Prevention of Significant Deterioration Permit" or "PSD Permit" means a permit or the 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 165 of the CAA and 40 CFR 51.166.  [415 ILCS 5/3.363]

 

Section 204.580  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.

 

Section 204.590  Project

 

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

 

Section 204.600  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 if 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 State or federal regulatory authorities, and compliance plans under Illinois' SIP;

 

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 204.240 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 subsection (b)(1), may elect to use the emissions unit's potential to emit, in tons per year, as defined under Section 204.560.

 

Section 204.610  Regulated NSR Pollutant

 

"Regulated NSR pollutant" means the following:

 

a)         Any pollutant for which a NAAQS has been promulgated.  This includes, but is not limited to, the following:

 

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

 

2)         Any pollutant identified under this subsection as a constituent or precursor for a pollutant for which a NAAQS has been promulgated.  Precursors for purposes of this Part are the following:

 

A)        VOM and NO_X are precursors to ozone in all attainment and unclassifiable areas.

 

B)        SO₂ is a precursor to PM_2.5 in all attainment and unclassifiable areas.

 

C)        NO_X are presumed to be precursors to PM_2.5 in all attainment and unclassifiable areas, unless the State demonstrates to the satisfaction of USEPA or USEPA demonstrates that emissions of NO_X from sources in a specific area are not a significant contributor to that area's ambient PM_2.5 concentrations.

 

D)        VOM are presumed not to be precursors to PM_2.5 in any attainment or unclassifiable area, unless the State demonstrates to the satisfaction of USEPA or USEPA demonstrates that emissions of VOM from sources in a specific area are a significant contributor to that area's ambient PM_2.5 concentrations;

 

b)         Any pollutant that is subject to any standard promulgated under section 111 of the CAA (42 USC 7401);

 

c)         Any Class I or II substance subject to a standard promulgated under or established by title VI of the CAA (42 USC 7671, et seq.);

 

d)         Any pollutant that otherwise is subject to regulation, as defined in Section 204.700.

 

e)         Notwithstanding subsections (a) through (d), the term "regulated NSR pollutant" shall not include any or all hazardous air pollutants either listed in section 112(b)(1) of the CAA (42 USC 7412(b)(1)) or added to the list under CAA section 112(b)(2) or (b)(3), or substances listed under CAA section 112(r)(3) and that have not been delisted under CAA section 112(b)(3) or (r), unless the listed hazardous air pollutant is also regulated as a constituent or precursor of a pollutant listed under CAA section 108 (42 USC 7408).

 

Section 204.620  Replacement Unit

 

"Replacement unit" means an emissions unit for which all the criteria listed in this Section are met.  No creditable emission 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 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) are 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, 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:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.630  Repowering

 

a)         "Repowering" means replacement of an existing coal-fired boiler with one of the following clean coal technologies: atmospheric or pressurized fluidized bed combustion; integrated gasification combined cycle; magnetohydrodynamics; direct and indirect coal-fired turbines; integrated gasification fuel cells; or, as determined by USEPA in consultation with the U.S. Secretary of Energy, a derivative of one or more of these technologies and any other technology capable of controlling multiple combustion emissions simultaneously with improved boiler or generation efficiency and with significantly greater waste reduction relative to the performance of technology in widespread commercial use as of November 15, 1990.

 

b)         Repowering shall also include any oil and/or gas-fired unit that has been awarded clean coal technology demonstration funding as of January 1, 1991, by the U.S. Department of Energy.

 

c)         The Agency shall give expedited consideration to permit applications for any source that satisfies the requirements of this Section and is granted an extension under section 409 of the CAA (42 USC 7651h).

 

Section 204.640  Reviewing Authority

 

"Reviewing authority" means the Agency or, in the case of a permit program under 40 CFR 52.21, USEPA or its delegate (the Agency).

 

Section 204.650  Secondary Emissions

 

"Secondary emissions" means emissions that 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 that 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 that 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.

 

Section 204.660  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 and Emissions Rate
Carbon monoxide	100 tpy
NOX	40 tpy
SO2	40 tpy
PM	25 tpy of particulate matter emissions
PM10	15 tpy
PM2.5	10 tpy of direct PM2.5 emissions; 40 tpy of SO2 emissions; 40 tpy of NOX emissions unless demonstrated not to be a PM2.5 precursor under Section 204.610(a)(2)(C)
Ozone	40 tpy of VOM or NOX
Lead	0.6 tpy
Fluorides	3 tpy
Sulfuric acid mist	7 tpy
Hydrogen sulfide (H2S)	10 tpy
Total reduced sulfur (including H2S)	10 tpy
Reduced sulfur compounds (including H2S)	10 tpy
GHGs	75,000 tpy CO2e
Municipal waste combustor organics (measured as total tetra-through octa-chlorinated dibenzo-p-dioxins and dibenzofurans)	3.2 ×10-6 megagrams per year (3.5 ×10-6 tpy)
Municipal waste combustor metals (measured as PM)	14 megagrams per year (15 tpy)
Municipal waste combustor acid gases (measured as SO2 and hydrogen chloride)	36 megagrams per year (40 tpy)
Municipal solid waste landfills emissions (measured as nonmethane organic compounds)	45 megagrams per year (50 tpy)
Ozone depleting substances	100 tpy

 

b)         "Significant" means, in reference to a net emissions increase or the potential of a source to emit a regulated NSR pollutant that subsection (a) does not list, any emissions rate.

 

c)         Notwithstanding subsection (a), "significant" means any emissions rate or any net emissions increase associated with a major stationary source or major modification that would construct within 10 kilometers of a Class I area, and have an impact on that area equal to or greater than 1 μg/m³ (24-hr average).

 

Section 204.670  Significant Emissions Increase

 

"Significant emissions increase" means, for a regulated NSR pollutant, an increase in emissions that is significant (as defined in Section 204.660) for that pollutant.

 

Section 204.680  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.

 

Section 204.690  Stationary Source

 

"Stationary source" means any building, structure, facility, or installation that 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 USC 7550) are not a part of a stationary source.

 

Section 204.700  Subject to Regulation

 

"Subject to regulation" means, for any air pollutant, that the pollutant is subject to either a provision in the CAA, or a nationally-applicable regulation codified by USEPA in 40 CFR 50 through 99, that requires actual control of the quantity of emissions of that pollutant, and that such a control requirement has taken effect and is operative to control, limit or restrict the quantity of emissions of that pollutant released from the regulated activity.  Pollutants subject to regulation include, but are not limited to, GHGs as defined in Section 204.430.

 

Section 204.710  Temporary Clean Coal Technology Demonstration Project

 

"Temporary clean coal technology demonstration project" means a clean coal technology demonstration project that is operated for a period of 5 years or less and that complies with Illinois' SIP and other requirements necessary to attain and maintain the NAAQS during the project and after it is terminated.

 

Section 204.800  Applicability

 

a)         The requirements of this Part apply to the construction of any new major stationary source (as defined in Section 204.510) or any project at an existing major stationary source in an area designated as attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the CAA (42 USC 7407(d)(1)(A)(ii) or (iii)).

 

b)         The requirements of Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, and 204.1200 apply to the construction of any new major stationary source or the major modification of any existing major stationary source, except as this Part otherwise provides.

 

c)         No new major stationary source or major modification to which the requirements of Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, and 204.1200 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.

 

d)         The requirements of the program will be applied in accordance with the principles set out in this subsection.

 

1)         Except as otherwise provided in subsection (f), and consistent with the definition of major modification contained in Section 204.490, 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 204.670) and a significant net emissions increase (as defined in Sections 204.550 and 204.660).  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 (d)(3) through (d)(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 204.550.  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 204.600) and the baseline actual emissions (as defined in Section 204.240(a) and (b)), for each existing emissions unit, equals or exceeds the significant amount for that pollutant (as defined in Section 204.660).

 

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 204.560) from each new emissions unit following completion of the project and the baseline actual emissions (as defined in Section 204.240(c)) of these units before the project equals or exceeds the significant amount for that pollutant (as defined in Section 204.660).

 

5)         Hybrid Test for Projects That Involve Multiple Types of Emissions Unit or 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 (d)(3) and (d)(4) as applicable with respect to each emissions unit, for each type of emissions unit equals or exceeds the significant amount for that pollutant (as defined in Section 204.660).

 

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

 

e)         Except as otherwise provided in Section 204.1400(f)(2), the provisions of Section 204.1400 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 204.1400(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 204.600(b) for calculating projected actual emissions.

 

f)         For any major stationary source for a PAL for a regulated NSR pollutant, the major stationary source shall comply with Subpart K.

 

g)         The provisions of 35 Ill. Adm. Code 203, Subpart R apply with respect to any regulated NSR pollutant emitted from the construction of any new major stationary source as defined in 35 Ill. Adm. Code 203.1230(a)(8) or any major modification as defined in 35 Ill. Adm. Code 203.1220 in an area designated as attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the CAA (42 U.S.C. 7407(d)(1)(A)(ii) or (iii)) if the emissions from the major stationary source or major modification would cause or contribute to a violation of any NAAQS.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.810  Source Information

 

The owner or operator of a proposed major stationary source or major modification shall submit all information necessary to perform any analysis or make any determination required under this Part.

 

a)         With respect to a source or modification to which Sections 204.1100, 204.1110, 204.1130, and 204.1140 apply, such information shall include:

 

1)         A description of the nature, location, design capacity, and typical operating schedule of the source or modification, including specifications and drawings showing its design and plant layout;

 

2)         A detailed schedule for construction of the source or modification; and

 

3)         A detailed description as to what system of continuous emission reduction is planned for the source or modification, emission estimates, and any other information necessary to determine that BACT, as applicable, would be applied.

 

b)         Upon request of the Agency, the owner or operator shall also provide information on:

 

1)         The air quality impact of the source or modification, including meteorological and topographical data necessary to estimate that impact; and

 

2)         The air quality impacts, and the nature and extent of any or all general commercial, residential, industrial, and other growth that has occurred since August 7, 1977, in the area the source or modification would affect.

 

Section 204.820  Source Obligation

 

Any owner or operator who constructs or operates a source or modification not in accordance with the application submitted under this Part or with the terms of any approval to construct, or any owner or operator of a source or modification subject to this Part who begins actual construction after September 4, 2020 without applying for and receiving approval under this Part, shall be subject to appropriate enforcement action.

 

Section 204.830  Permit Expiration

 

Approval to construct shall become invalid if construction is not commenced within 18 months after receipt of approval, if construction is discontinued for a period of 18 months or more, or if construction is not completed within a reasonable time.  The Agency may extend the 18-month period upon a satisfactory showing that an extension is justified.  This provision does not apply to the time period between construction of the approved phases of a phased construction project; each phase must commence construction within 18 months after the projected and approved commencement date.

 

Section 204.840  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.

 

Section 204.850  Relaxation of a Source-Specific Limitation

 

At such time as a particular source or modification becomes a major stationary source or major modification solely by virtue of a relaxation in any enforceable limitation, 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 Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, 204.1200, and 204.1400 shall apply to the source or modification as though construction had not yet commenced on the source or modification.

 

Section 204.860  Exemptions

 

a)         The requirements of Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, 204.1200, and 204.1400 do not apply to a particular major stationary source or major modification, if:

 

1)         The source or modification would be a nonprofit health or nonprofit educational institution, or a major modification would occur at such an institution and the Governor of Illinois exempts it from those requirements; or

 

2)         The source or modification would be a major stationary source or major modification only if fugitive emissions, to the extent quantifiable, are considered in calculating the potential to emit of the stationary source or modification and the source does not belong to any of the following categories:

 

A)        Coal cleaning plants (with thermal dryers);

 

B)        Kraft pulp mills;

 

C)        Portland cement plants;

 

D)        Primary zinc smelters;

 

E)        Iron and steel mills;

 

F)         Primary aluminum ore reduction plants;

 

G)        Primary copper smelters;

 

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

 

I)         Hydrofluoric, sulfuric, or nitric acid plants;

 

J)         Petroleum refineries;

 

K)        Lime plants;

 

L)        Phosphate rock processing plants;

 

M)       Coke oven batteries;

 

N)        Sulfur recovery plants;

 

O)        Carbon black plants (furnace process);

 

P)         Primary lead smelters;

 

Q)        Fuel conversion plants;

 

R)        Sintering plants;

 

S)         Secondary metal production plants;

 

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

 

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

 

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

 

W)       Taconite ore processing plants;

 

X)        Glass fiber processing plants;

 

Y)        Charcoal production plants;

 

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

 

AA)     Any other stationary source category that, as of August 7, 1980, is being regulated under section 111 or 112 of the CAA (42 USC 7411 or 7412); or

 

3)         The source is a portable stationary source that has previously received a permit under 40 CFR 52.21 or this Part and:

 

A)        The owner or operator proposes to relocate the source and emissions of the source at the new location would be temporary;

 

B)        The emissions from the source would not exceed its allowable emissions;

 

C)        The emissions from the source would impact no Class I area and no area where an applicable increment is known to be violated; and

 

D)        Reasonable notice is given to the Agency prior to the relocation identifying the proposed new location and the probable duration of operation at the new location.  Such notice shall be given to the Agency not less than 10 days in advance of the proposed relocation unless a different time duration is previously approved by the Agency.

 

b)         The requirements of Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, 204.1200, and 204.1400 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 under section 107 of the CAA (42 USC 7407).  Nonattainment designations for revoked NAAQS, as contained in 40 CFR 81 (incorporated by reference in Section 204.100), shall not be viewed as current designations under section 107 of the CAA (42 USC 7407) for purposes of determining the applicability of Sections 204.810, 204.820, 204.830, 204.840, 204.850, 204.1100, 204.1110, 204.1120, 204.1130, 204.1140, 204.1200, and 204.1400 to a major stationary source or major modification after the revocation of that NAAQS is effective.

 

c)         The requirements of Sections 204.1110, 204.1130, and 204.1140 shall not apply to a major stationary source or major modification with respect to a particular pollutant if the allowable emissions of that pollutant from the source, or the net emissions increase of that pollutant from the modification:

 

1)         Would impact no Class I area and no area where an applicable increment is known to be violated; and

 

2)         Would be temporary.

 

d)         The requirements of Sections 204.1110, 204.1130, and 204.1140 as they relate to any maximum allowable increase for a Class II area shall not apply to a major modification at a stationary source that was in existence on March 1, 1978, if the net increase in allowable emissions of each regulated NSR pollutant from the modification after the application of BACT would be less than 50 tpy.

 

Section 204.900  Ambient Air Increments

 

a)         In areas designated as Class I, II or III, increases in pollutant concentration over the baseline concentration shall be limited to the following:

 

Pollutant	Maximum allowable increase (micrograms per cubic meter)
Class I Area
PM2.5:
Annual arithmetic mean	1
24-hr maximum	2
PM10:
Annual arithmetic mean	4
24-hr maximum	8
SO2:
Annual arithmetic mean	2
24-hr maximum	5
3-hr maximum	25
NO2:
Annual arithmetic mean	2.5
Class II Area
PM2.5:
Annual arithmetic mean	4
24-hr maximum	9
PM10:
Annual arithmetic mean	17
24-hr maximum	30
SO2:
Annual arithmetic mean	20
24-hr maximum	91
3-hr maximum	512
NO2:
Annual arithmetic mean	25
Class III Area
PM2.5:
Annual arithmetic mean	8
24-hr maximum	18
PM10:
Annual arithmetic mean	34
24-hr maximum	60
SO2:
Annual arithmetic mean	40
24-hr maximum	182
3-hr maximum	700
NO2:
Annual arithmetic mean	50

 

b)         For any period other than an annual period, the applicable maximum allowable increase may be exceeded during one such period per year at any one location.

 

Section 204.910  Ambient Air Ceilings

 

No concentration of a pollutant shall exceed:

 

a)         The concentration permitted under the national secondary ambient air quality standard; or

 

b)         The concentration permitted under the national primary ambient air quality standard, whichever concentration is lowest for the pollutant for a period of exposure.

 

Section 204.920  Restrictions on Area Classifications

 

a)         All of the following areas that were in existence on August 7, 1977 shall be Class I areas and may not be redesignated:

 

1)         International parks;

 

2)         National wilderness areas that exceed 5,000 acres in size;

 

3)         National memorial parks that exceed 5,000 acres in size; and

 

4)         National parks that exceed 6,000 acres in size.

 

b)         Areas which were redesignated as Class I under regulations promulgated before August 7, 1977 shall remain Class I, but may be redesignated as provided in this Part.

 

c)         Any other area, unless otherwise specified in the legislation creating such an area, is initially designated Class II, but may be redesignated as provided in this Part.

 

d)         The following areas may be redesignated only as Class I or II:

 

1)         An area that, as of August 7, 1977, exceeded 10,000 acres in size and was a national monument, a national primitive area, a national preserve, a national recreational area, a national wild and scenic river, a national wildlife refuge, a national lakeshore or seashore; and

 

2)         A national park or national wilderness area established after August 7, 1977 that exceeds 10,000 acres in size.

 

Section 204.930  Redesignation

 

a)         As of September 4, 2020, all areas of the State (except as otherwise provided by Section 204.920) are designated Class II as of December 5, 1974.  Redesignation (except as otherwise precluded by Section 204.920) may be proposed by the State or Indian Governing Bodies under this Section, subject to approval by USEPA as a revision to the applicable SIP.

 

b)         The State may submit to USEPA a proposal to redesignate areas of the State Class I or Class II provided that:

 

1)         At least one public hearing has been held in accordance with 35 Ill. Adm. Code 252;

 

2)         Other states, Indian Governing Bodies, and Federal Land Managers whose lands may be affected by the proposed redesignation were notified at least 30 days prior to the public hearing;

 

3)         A discussion of the reasons for the proposed redesignation, including a satisfactory description and analysis of the health, environmental, economic, social, and energy effects of the proposed redesignation, was prepared and made available for public inspection at least 30 days prior to the hearing and the notice announcing the hearing contained appropriate notification of the availability of such discussion;

 

4)         Prior to the issuance of notice respecting the redesignation of an area that includes any federal lands, the State has provided written notice to the appropriate Federal Land Manager and afforded adequate opportunity (not in excess of 60 days) to confer with the State respecting the redesignation and to submit written comments and recommendations.  In redesignating any area with respect to which any Federal Land Manager had submitted written comments and recommendations, the State shall have published a list of any inconsistency between such redesignation and such comments and recommendations (together with the reasons for making such redesignation against the recommendation of the Federal Land Manager); and

 

5)         The State has proposed the redesignation after consultation with the elected leadership of local and other substate general purpose governments in the area covered by the proposed redesignation.

 

c)         Any area other than an area to which Section 204.920 refers may be redesignated as Class III if:

 

1)         The redesignation would meet the requirements of subsection (b);

 

2)         The redesignation, except any established by an Indian Governing Body, has been specifically approved by the Governor of Illinois:

 

A)        After consultation with the appropriate committees of the legislature, if it is in session, or with the leadership of the legislature, if it is not in session (unless State law provides that the redesignation must be specifically approved by State legislation); and

 

B)        If general purpose units of local government representing a majority of the residents of the area to be redesignated enact legislation or pass resolutions concurring in the redesignation;

 

3)         The redesignation would not cause, or contribute to, a concentration of any air pollutant that would exceed any maximum allowable increase permitted under the classification of any other area or any NAAQS; and

 

4)         Any permit application for any major stationary source or major modification, subject to review under Section 204.1120, that could receive a permit under this Part only if the area in question were redesignated as Class III, and any material submitted as part of that application, were available, insofar as was practicable for public inspection prior to any public hearing on redesignation of the area as Class III.

 

d)         Lands within the exterior boundaries of Indian Reservations may be redesignated only by the appropriate Indian Governing Body.  The appropriate Indian Governing Body may submit to USEPA a proposal to redesignate areas Class I, Class II, or Class III, provided that:

 

1)         The Indian Governing Body has followed procedures equivalent to those required of a state under subsections (b), (c)(3), and (c)(4); and

 

2)         Such redesignation is proposed after consultation with the State or States in which the Indian Reservation is located and that border the Indian Reservation.

 

e)         USEPA shall disapprove, within 90 days after submission, a proposed redesignation of any area only if it finds, after notice and opportunity for public hearing, that such redesignation does not meet the procedural requirements or is inconsistent with Section 204.920.  If any such disapproval occurs, the classification of the area shall be that which was in effect prior to the redesignation which was disapproved.

 

f)         If USEPA disapproves any proposed redesignation, the State or Indian Governing Body, as appropriate, may resubmit the proposal after correcting the deficiencies noted by USEPA.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.1000  Stack Heights

 

a)         The degree of emission limitation required for control of any air 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)         Subsection (a) shall not apply with respect to stack heights in existence before December 31, 1970 or to dispersion techniques implemented before then.

 

Section 204.1100  Control Technology Review

 

a)         A major stationary source or major modification shall meet each applicable emissions limitation under the SIP and each applicable emissions standard and standard of performance under 40 CFR 60, 61, 62 and 63 (incorporated by reference in Section 204.100).

 

b)         A new major stationary source shall apply BACT for each regulated NSR pollutant that it would have the potential to emit in significant amounts (defined in Section 204.660).

 

c)         A major modification shall apply BACT for each regulated NSR pollutant for which it would result in a significant net emissions increase at the source.  This requirement applies to each proposed emissions unit at which a net emissions increase in the pollutant would occur as a result of a physical change or change in the method of operation in the unit.

 

d)         For phased construction projects, the determination of BACT shall be reviewed and modified as appropriate at the latest reasonable time that occurs no later than 18 months prior to commencement of construction of each independent phase of the project.  At such time, the owner or operator of the applicable stationary source may be required to demonstrate the adequacy of any previous determination of BACT for the source.

 

Section 204.1110  Source Impact Analysis

 

The owner or operator of the proposed source or modification shall demonstrate that allowable emission increases from the proposed source or modification, in conjunction with all other applicable emissions increases or reductions (including secondary emissions), would not cause or contribute to air pollution in violation of:

 

a)         Any NAAQS in any air quality control region; or

 

b)         Any applicable maximum allowable increase as set forth in Section 204.900 and/or Section 204.1200, as applicable, over the baseline concentration in any area.

 

Section 204.1120  Air Quality Models

 

a)         All estimates of ambient concentrations required under this Section shall be based on applicable air quality models, databases, and other requirements specified in 40 CFR 51, appendix W (Guideline on Air Quality Models) (incorporated by reference in 35 Ill. Adm. Code 204.100).

 

b)         When an air quality model specified in 40 CFR 51, appendix W (Guideline on Air Quality Models) (incorporated by reference in Section 204.100) is inappropriate, the model may be modified or another model substituted.  Such a modification or substitution of a model may be made on a case-by-case basis or, where appropriate, on a generic basis for a specific State program.  Written approval of USEPA must be obtained for any modification or substitution.  In addition, use of a modified or substituted model must be subject to notice and opportunity for public comment under procedures set forth in 35 Ill. Adm. Code 252.

 

Section 204.1130  Air Quality Analysis

 

a)         Preapplication Analysis

 

1)         Any application for a permit under this Part shall contain an analysis of ambient air quality in the area that the major stationary source or major modification would affect for each of the following pollutants:

 

A)        For the source, each pollutant that it would have the potential to emit in a significant amount;

 

B)        For the modification, each pollutant for which it would result in a significant net emissions increase.

 

2)         With respect to any such pollutant for which no NAAQS exists, the analysis shall contain air quality monitoring data the Agency determines is necessary to assess ambient air quality for that pollutant in any area that the emissions of that pollutant would affect.

 

3)         With respect to any such pollutant for which such a NAAQS does exist, the analysis shall contain continuous air quality monitoring data gathered for purposes of determining whether emissions of that pollutant would cause or contribute to a violation of the standard or any maximum allowable increase.

 

4)         In general, the continuous air quality monitoring data that is required shall have been gathered over a period of at least one year and shall represent at least the year preceding receipt of the application.  However, if the Agency determines that a complete and adequate analysis can be accomplished with monitoring data gathered over a period shorter than one year (but not less than four months), the data that is required shall have been gathered over at least that shorter period.

 

5)         The owner or operator of a proposed stationary source or modification of VOM who satisfies all conditions of 40 CFR 51, appendix S, section IV, (incorporated by reference in Section 204.100) may provide post-approval monitoring data for ozone in lieu of providing preconstruction data as required by this subsection (a).

 

b)         Postconstruction Monitoring.  The owner or operator of a major stationary source or major modification shall, after construction of the stationary source or modification, conduct such ambient monitoring as the Agency determines is necessary to determine the effect emissions from the stationary source or modification may have, or are having, on air quality in any area.

 

c)         Operations of Monitoring Stations.  The owner or operator of a major stationary source or major modification shall meet the requirements of 40 CFR 58, appendix B (incorporated by reference in Section 204.100), during the operation of monitoring stations for purposes of satisfying this Section.

 

Section 204.1140  Additional Impact Analyses

 

a)         The owner or operator shall provide an analysis of the impairment to visibility, soils and vegetation that would occur as a result of the source or modification and general commercial, residential, industrial and other growth associated with the source or modification.  The owner or operator need not provide an analysis of the impact on vegetation having no significant commercial or recreational value.

 

b)         Such owner or operator shall provide an analysis of the air quality impact projected for the area as a result of general commercial, residential, industrial and other growth associated with the source or modification.

 

Section 204.1200  Additional Requirements for Sources Impacting Federal Class I Areas

 

a)         Notice to Federal Land Managers.  The Agency shall provide written notice of any permit application for a proposed major stationary source or major modification, the emissions from which may affect a Class I area, to the Federal Land Manager and the federal official charged with direct responsibility for management of any lands within any such area.  Such notification shall include a copy of all information relevant to the permit application and shall be given within 30 days after receipt and at least 60 days prior to any public hearing on the application for a permit to construct.  Such notification shall include an analysis of the proposed source's anticipated impacts on visibility in the Federal Class I area.  The Agency shall also provide the Federal Land Manager and such federal officials with a copy of the preliminary determination required by 35 Ill. Adm. Code 252, and shall make available to them any materials used in making that determination, promptly after the Agency makes such determination.  Finally, the Agency shall also notify all affected Federal Land Managers within 30 days after receipt of any advance notification of any such permit application.

 

b)         Federal Land Manager.  The Federal Land Manager and the federal official charged with direct responsibility for management of such lands have an affirmative responsibility to protect the air quality related values (including visibility) of such lands and to consider, in consultation with the Agency, whether a proposed source or modification will have an adverse impact on such values.

 

c)         Visibility Analysis.  The Agency shall consider any analysis performed by the Federal Land Manager, provided within 30 days after the notification required by subsection (a), that shows that a proposed new major stationary source or major modification may have an adverse impact on visibility in any Federal Class I area.  When the Agency finds that such an analysis does not demonstrate to its satisfaction that an adverse impact on visibility will result in the Federal Class I area, the Agency must, in the notice of public hearing on the permit application, either explain its decision or give notice as to where the explanation can be obtained.

 

d)         Denial; Impact On Air Quality Related Values.  The Federal Land Manager of any such lands may demonstrate to the Agency that the emissions from a proposed source or modification would have an adverse impact on the air quality-related values (including visibility) of those lands, notwithstanding that the change in air quality resulting from emissions from such source or modification would not cause or contribute to concentrations that would exceed the maximum allowable increases for a Class I area.  If the Agency concurs with such demonstration, it shall not issue the permit.

 

e)         Class I Variances.  The owner or operator of a proposed source or modification may demonstrate to the Federal Land Manager that the emissions from such source or modification would have no adverse impact on the air quality related values of any such lands (including visibility), notwithstanding that the change in air quality resulting from emissions from such source or modification would cause or contribute to concentrations that would exceed the maximum allowable increases for a Class I area.  If the Federal Land Manager concurs with such demonstration and so certifies, the Agency may, provided that the applicable requirements of this Part are otherwise met, issue the permit with such emission limitations as may be necessary to assure that emissions of SO₂, PM_2.5, PM₁₀, and NO_X would not exceed the following maximum allowable increases over minor source baseline concentration for such pollutants:

 

Pollutant	Maximum allowable increase (micrograms per cubic meter)
PM2.5:
Annual arithmetic mean	4
24-hr maximum	9
PM10:
Annual arithmetic mean	17
24-hr maximum	30
SO2:
Annual arithmetic mean	20
24-hr maximum	91
3-hr maximum	325
NO2:
Annual arithmetic mean	25

 

f)         Sulfur Dioxide Variance by Governor with Federal Land Manager's Concurrence. The owner or operator of a proposed source or modification that cannot be approved under subsection (e) may demonstrate to the Governor that the source cannot be constructed by reason of any maximum allowable increase for SO₂ for a period of 24 hours or less applicable to any Class I area and, in the case of federal mandatory Class I areas, that a variance under this subsection would not adversely affect the air quality related values of the area (including visibility).  The Governor, after consideration of the Federal Land Manager's recommendation (if any) and subject to his or her concurrence, may, after notice and public hearing, grant a variance from such maximum allowable increase.  If such variance is granted, the Agency shall issue a permit to such source or modification under subsection (h), provided that the applicable requirements of this Part are otherwise met.

 

g)         Variance by the Governor with the President's Concurrence.  In any case in which the Governor recommends a variance in which the Federal Land Manager does not concur, the recommendations of the Governor and the Federal Land Manager shall be transmitted to the President.  The President may approve the Governor's recommendation if the President finds that the variance is in the national interest.  If the variance is approved, the Agency shall issue a permit under subsection (h), provided that the applicable requirements of this Part are otherwise met.

 

h)         Emissions Limitations for Presidential or Gubernatorial Variance.  In the case of a permit issued under subsection (f) or (g), the source or modification shall comply with such emission limitations as may be necessary to assure that emissions of SO₂ from the source or modification would not (during any day on which the otherwise applicable maximum allowable increases are exceeded) cause or contribute to concentrations that would exceed the following maximum allowable increases over the baseline concentration and to assure that such emissions would not cause or contribute to concentrations that exceed the otherwise applicable maximum allowable increases for periods of exposure of 24 hours or less for more than 18 days, not necessarily consecutive, during any annual period:

 

MAXIMUM ALLOWABLE INCREASE (Micrograms per cubic meter)
Period of exposure	Low Terrain	High Terrain
24-hr maximum	36	62
3-hr maximum	130	221

 

 

Section 204.1300  Notification of Application Completeness to Applicants

 

The Agency shall notify the applicant within 30 days after receipt as to the completeness of an application for a permit under this Part or any deficiency in the application or information submitted in such an application.  In the event of such a deficiency, the date of receipt of the application shall be the date on which the Agency receives all required information.

 

Section 204.1310  Transmittal of Application to USEPA

 

The Agency shall transmit to USEPA a copy of each permit application submitted under this Part relating to a major stationary source or a major modification.

 

Section 204.1320  Public Participation

 

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

 

Section 204.1330  Issuance Within One Year of Submittal of Complete Application

 

Within one year after receipt of a complete application, a permit shall be granted or denied by the Agency.

 

Section 204.1340  Permit Rescission

 

a)         Any permit issued under this Part or a prior version of this Part shall remain in effect unless and until it expires under Section 204.830 or is rescinded under this Section.

 

b)         An owner or operator of a stationary source or modification who holds a permit issued under this Part or 40 CFR 52.21 for the construction of a new source or modification that meets the requirement in subsection (c) may request that the Agency rescind the permit or a particular portion of the permit.

 

c)         The Agency may grant an application for rescission if the application shows that this Part would not apply to the source or modification.

 

d)         If the Agency rescinds a permit under this Section, it shall post a notice of the rescission determination on a public web site identified by it within 60 days after the rescission.

 

Section 204.1400  Recordkeeping and Reporting Requirements for Certain Projects at Major Stationary Sources

 

Except as otherwise provided in subsection (f)(2), 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 (other than projects at a source with a PAL) in circumstances in which 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 204.600(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 204.600(b)(3), 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 204.660) 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 percent of the amount that is a "significant emissions increase", as defined in Section 204.670 (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 204.600(b)(3), sums to at least 50 percent of the amount that is a "significant emissions increase", as defined under Section 204.670 (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 under this Section available for review upon a request for inspection by the Agency or USEPA or the general public pursuant to the requirements contained in Section 39.5(8)(e) of the Act.

 

Section 204.1500  Innovative Control Technology

 

a)         An owner or operator of a proposed major stationary source or major modification may request that the Agency in writing no later than the close of the comment period under 35 Ill. Adm. Code 252 to approve a system of innovative control technology.

 

b)         The Agency shall, with the consent of the other affected State's Governor or other affected States' respective Governors, determine that the source or modification may employ a system of innovative control technology if:

 

1)         The proposed control system would not cause or contribute to an unreasonable risk to public health, welfare, or safety in its operation or function;

 

2)         The owner or operator agrees to achieve a level of continuous emissions reduction equivalent to that which would have been required under Section 204.1100(b), by a date specified by the Agency.  Such date shall not be later than 4 years after the time of startup or 7 years after permit issuance;

 

3)         The source or modification would meet the requirements of Sections 204.1100 and 204.1110, based on the emissions rate that the stationary source employing the system of innovative control technology would be required to meet on the date specified by the Agency;

 

4)         The source or modification would not, before the date specified by the Agency:

 

A)        Cause or contribute to a violation of an applicable NAAQS; or

 

B)        Impact any area where an applicable increment is known to be violated;

 

5)         All other applicable requirements, including those for public participation, have been met; and

 

6)         The provisions of Section 204.1200 (relating to Class I areas) have been satisfied with respect to all periods during the life of the source or modification.

 

c)         The Agency shall withdraw any approval to employ a system of innovative control technology made under this Section if:

 

1)         The proposed system fails by the specified date to achieve the required continuous emissions reduction rate;

 

2)         The proposed system fails before the specified date so as to contribute to an unreasonable risk to public health, welfare, or safety; or

 

3)         The Agency decides at any time that the proposed system is unlikely to achieve the required level of control or to protect the public health, welfare, or safety.

 

d)         If a source or modification fails to meet the required level of continuous emissions reduction within the specified time period or the approval is withdrawn in accordance with subsection (c), the Agency may allow the source or modification up to an additional 3 years to meet the requirement for the application of BACT through use of a demonstrated system of control.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.1600  Applicability

 

a)         The Agency may approve the use of an actuals PAL for any existing major stationary source if the PAL meets the requirements of this Subpart.  The term "PAL" shall mean "actuals PAL" throughout this Subpart.

 

b)         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 204.850 (restrictions on relaxing enforceable emission limitations that the major stationary source used to avoid applicability of the major NSR program).

 

c)         Except as provided by subsection (b)(2), a major stationary source shall continue to comply with all applicable federal or State requirements, emissions limitations, and work practice requirements that were established prior to the effective date of the PAL.

 

Section 204.1610  Definitions

 

For the purposes of this Subpart, the definitions in Sections 204.1620 through 204.1780 apply. When a term is not defined in these Sections, it shall have the meaning given in this Part, 35 Ill. Adm. Code 211, or the CAA.

 

Section 204.1620  Actuals PAL

 

"Actuals PAL", for a major stationary source, means a PAL based on the baseline actual emissions (as defined in Section 204.240) of all emissions units (as defined in Section 204.370) at the source that emit or have the potential to emit the PAL pollutant.

 

Section 204.1630  Allowable Emissions

 

"Allowable emissions" means "allowable emissions" as defined in Section 204.230, 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.

 

Section 204.1640  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 Part, to sample, condition (if applicable), analyze, and provide a record of emissions on a continuous basis.

 

Section 204.1650  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).

 

Section 204.1660  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 Part 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.

 

Section 204.1670  Lowest Achievable Emission Rate (LAER)

 

"Lowest achievable emission rate" or "LAER" has the meaning given by 35 Ill. Adm. Code 203.

 

(Source:  Amended at 49 Ill. Reg. 6332, effective April 23, 2025)

 

Section 204.1680  Major Emissions Unit

 

"Major emissions unit" means any emissions unit that emits or has the potential to emit 100 tpy or more of the PAL pollutant in an attainment area.

 

Section 204.1690  Plantwide Applicability Limitation (PAL)

 

"Plantwide applicability limitation" or "PAL" means an emission limitation expressed on a mass basis in tons per year, or expressed in tons per year CO₂e for a GHG emission limitation for a pollutant at a major stationary source, that is enforceable as a practical matter and established source-wide in accordance with this Subpart.

 

Section 204.1700  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.

 

Section 204.1710  PAL Effective Period

 

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

 

Section 204.1720  PAL Major Modification

 

"PAL major modification" means, notwithstanding Sections 204.490 and 204.550 (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.

 

Section 204.1730  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.

 

Section 204.1740  PAL Pollutant

 

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

 

Section 204.1750  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 to calculate and record the mass emissions rate (e.g., lb/hr) on a continuous basis.

 

Section 204.1760  Reasonably Achievable Control Technology (RACT)

 

"Reasonably Achievable 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.

 

Section 204.1770  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 significant level (as defined in Section 204.660 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 204.1680).

 

Section 204.1780  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 204.660 or in the CAA, whichever is lower.

 

Section 204.1790  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 204.1890(a).

 

Section 204.1800  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, or expressed in tons per year CO₂e for a GHG PAL, 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 average, rolled monthly).  For each month during the first 11 months after 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 204.1810.

 

3)         The PAL permit shall contain all the requirements of Section 204.1830.

 

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 Sections 204.1880 through 204.1900 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 35 Ill. Adm. Code 203 unless the level of the PAL is reduced by the amount of those emissions reductions and the reductions would be creditable in the absence of the PAL.

 

Section 204.1810  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 provide 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.

 

Section 204.1820  Setting the 10-Year Actuals PAL Level

 

a)         Except as provided in subsection (b), the plan shall provide that the actuals PAL level for a major stationary source shall be established as the sum of the baseline actual emissions (as defined in Section 204.240) of the PAL pollutant for each emissions unit at the source, plus an amount equal to the applicable significant level for the PAL pollutant under Section 204.660 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 in the PAL permit a reduced PAL level or levels in tons per year (or tons per year CO₂e for a GHG PAL) 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 to half the baseline emissions of 60 ppm NO_X to a new rule limit of 30 ppm, 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 emissions of the 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.

 

Section 204.1830  Contents of the PAL Permit

 

The PAL permit must contain, at a minimum:

 

a)         The PAL pollutant and the applicable source-wide emission limitation in tons per year, or tons per year CO₂e for a GHG PAL.

 

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 accordance with Section 204.1860 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 204.1850.

 

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 204.1890(a).

 

g)         A requirement that the major stationary source owner or operator monitor all emissions units in accordance with the provisions under Section 204.1880.

 

h)         A requirement to retain the records required by Section 204.1890 on site.  Such records may be retained in an electronic format.

 

i)          A requirement to submit the reports required by Section 204.1900 by the required deadlines.

 

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

 

Section 204.1840  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 must 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 offsets under 35 Ill. Adm. Code 203; and

 

C)        Revise the PAL to reflect an increase in the PAL as provided under Section 204.1870.

 

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; and

 

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 allowed by 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 accordance with the public participation requirements of Section 204.1810.

 

Section 204.1850  Expiration of a PAL

 

Any PAL that is not renewed in accordance with Section 204.1860 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 under this subsection (a).

 

1)         Within the time frame specified for PAL renewals in Section 204.1860(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 204.1860(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 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 by 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 204.490.

 

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 204.850, but were eliminated by the PAL in accordance with Section 204.1600(b)(3).

 

Section 204.1860  Renewal of a PAL

 

a)         The Agency shall follow the procedures specified in Section 204.1810 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 before, but not earlier than 18 months before, 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, 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 204.1790.

 

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 (d)(2).  However, in no case may any such adjustment fail to comply with subsection (d)(3).

 

1)         If the emissions level calculated in accordance with Section 204.1820 is equal to or greater than 80 percent 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 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 subsection (d)(1):

 

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 204.1870 (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 that requirement, the PAL shall be adjusted at the time of PAL permit renewal or CAAPP permit renewal, whichever occurs first.

 

Section 204.1870  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 this subsection (a).

 

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 or units 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, BACT), 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 must 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 204.1810.

 

Section 204.1880  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, or in CO₂e per unit of time for a GHG PAL.  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 minimum requirements set forth in subsection (b) 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 accordance with the minimum 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)         When the vendor of a material or fuel, that is used in or at the emissions unit, publishes a range of pollutant content from that 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 60, appendix B (incorporated by reference in Section 204.100); 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 after 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 those periods is specified in the PAL permit.

 

h)         Notwithstanding the requirements of subsections (c) through (g), when 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 a default value or values for determining compliance with the PAL based on the highest potential emissions reasonably estimated at the operating point or 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)          Revalidation.  All data used to establish the PAL pollutant must be revalidated 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.

 

Section 204.1890  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.

 

Section 204.1900  Reporting and Notification Requirements

 

The owner or operator shall submit semiannual monitoring reports and prompt deviation reports to the Agency in accordance with the CAAPP.  The reports shall meet the requirements of this Section.

 

a)         Semiannual Report.  The semiannual 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 subsection (a).

 

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

 

2)         Total annual emissions (expressed on a mass-basis in tons per year, or expressed in tons per year CO₂e for a GHG PAL) based on a 12-month rolling total for each month in the reporting period recorded under Section 204.1890(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 the method included in the permit, as provided by Section 204.1880(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 when no monitoring is available.  A report submitted under 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)         Revalidation Results.  The owner or operator shall submit to the Agency the results of any revalidation test or method within 3 months after completion of such test or method.

 

Section 204.1910  Transition Requirements

 

The Agency may not issue a PAL that does not comply with this Subpart after September 4, 2020.