Illinois Administrative Code

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…

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 paramet…

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 …

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 t…

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 t…

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 current…

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 su…

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 …

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 sm…

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 ba…

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 notic…

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 …

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 PA…

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,…

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…

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…

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 applicat…

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 f…

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 roll…

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 se…

Section 204.1910 Transition Requirements The Agency may not issue a PAL that does not comply with this Subpart after September 4, 2020.

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 signi…

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 …

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 operatio…

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 …

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 es…

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 b…

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 …

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 maj…

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 und…

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 NOX asso…

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…

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…

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 revie…

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 …

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 o…

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 …

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 204.42…