Ill. Admin. Code tit. 35, pt. 204

Prevention of Significant Deterioration

AUTHORITY: Implementing Sections 9.1 and 10 and authorized by Sections 27 and 28 of the Environmental Protection Act [415 ILCS 5/9.1, 10, 27 and 28]. SOURCE: Adopted in R19-1 at 44 Ill. Reg. 14923, effective September 4, 2020; amended in R22-17 at 49 Ill. Reg. 6332, effective April 23, 2025.POLLUTION CONTROL BOARD

204.100Incorporations by Reference 204.110Abbreviations and Acronyms 204.120Severability 204.200Definitions 204.210Actual Emissions 204.220Adverse Impact on Visibility 204.230Allowable Emissions 204.240Baseline Actual Emissions 204.250Baseline Area 204.260Baseline Concentration 204.270Begin Actual Construction 204.280Best Available Control Technology (BACT)204.290Building, Structure, Facility, or Installation 204.300Clean Coal Technology 204.310Clean Coal Technology Demonstration Project 204.320Commence 204.330Complete 204.340Construction 204.350Dispersion Technique 204.360Electric Utility Steam Generating Unit 204.370Emissions Unit 204.380Excessive Concentration 204.390Federal Land Manager 204.400Federally Enforceable 204.410Fugitive Emissions 204.420Good Engineering Practice 204.430Greenhouse Gases (GHGs)204.440High Terrain 204.450Indian Reservation 204.460Indian Governing Body 204.470Innovative Control Technology 204.480Low Terrain 204.490Major Modification 204.500Major Source Baseline Date 204.510Major Stationary Source 204.520Minor Source Baseline Date 204.530Nearby 204.540Necessary Preconstruction Approvals or Permits 204.550Net Emissions Increase 204.560Potential to Emit 204.570Prevention of Significant Deterioration (PSD) Permit 204.580Process Unit 204.590Project 204.600Projected Actual Emissions 204.610Regulated NSR Pollutant 204.620Replacement Unit 204.630Repowering 204.640Reviewing Authority 204.650Secondary Emissions 204.660Significant 204.670Significant Emissions Increase 204.680Stack in Existence 204.690Stationary Source 204.700Subject to Regulation 204.710Temporary Clean Coal Technology Demonstration Project 204.800Applicability 204.810Source Information 204.820Source Obligation 204.830Permit Expiration 204.840Effect of Permits 204.850Relaxation of a Source-Specific Limitation 204.860Exemptions 204.900Ambient Air Increments 204.910Ambient Air Ceilings 204.920Restrictions on Area Classifications 204.930Redesignation 204.1000Stack Heights 204.1100Control Technology Review 204.1110Source Impact Analysis 204.1120Air Quality Models 204.1130Air Quality Analysis 204.1140Additional Impact Analyses 204.1200Additional Requirements for Sources Impacting Federal Class I Areas 204.1300Notification of Application Completeness to Applicants 204.1310Transmittal of Application to USEPA 204.1320Public Participation 204.1330Issuance Within One Year of Submittal of Complete Application 204.1340Permit Rescission 204.1400Recordkeeping and Reporting Requirements for Certain Projects at Major Stationary Sources 204.1500Innovative Control Technology 204.1600Applicability 204.1610Definitions 204.1620Actuals PAL 204.1630Allowable Emissions 204.1640Continuous Emissions Monitoring System (CEMS)204.1650Continuous Emissions Rate Monitoring System (CERMS)204.1660Continuous Parameter Monitoring System (CPMS)204.1670Lowest Achievable Emission Rate (LAER)204.1680Major Emissions Unit 204.1690Plantwide Applicability Limitation (PAL)204.1700PAL Effective Date 204.1710PAL Effective Period 204.1720PAL Major Modification 204.1730PAL Permit 204.1740PAL Pollutant 204.1750Predictive Emissions Monitoring System (PEMS)204.1760Reasonably Achievable Control Technology (RACT)204.1770Significant Emissions Unit 204.1780Small Emissions Unit 204.1790Permit Application Requirements 204.1800General Requirements for Establishing PAL 204.1810Public Participation Requirements 204.1820Setting the 10-Year Actuals PAL Level 204.1830Contents of the PAL Permit 204.1840Effective Period and Reopening a PAL Permit 204.1850Expiration of a PAL 204.1860Renewal of a PAL 204.1870Increasing the PAL During the PAL Effective Period 204.1880Monitoring Requirements 204.1890Recordkeeping Requirements 204.1900Reporting and Notification Requirements 204.1910Transition Requirements