ADMINISTRATIVE CODE

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  4. CHAPTER I: POLLUTION CONTROL BOARD
TITLE 35: ENVIRONMENTAL PROTECTION
SUBTITLE F: PUBLIC WATER SUPPLIES
CHAPTER I: POLLUTION CONTROL BOARD
PART 620 GROUNDWATER QUALITY
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SUBPART A: GENERAL

Section 620.105 Purpose
Section 620.110 Definitions
Section 620.115 Prohibition
Section 620.125 Incorporations by Reference
Section 620.130 Exemption from General Use Standards and Public and Food Processing Water Supply Standards
Section 620.135 Exclusion for Underground Water in Certain Man-Made Conduits

SUBPART B: GROUNDWATER CLASSIFICATION

Section 620.201 Groundwater Designations
Section 620.210 Class I: Potable Resource Groundwater
Section 620.220 Class II: General Resource Groundwater
Section 620.230 Class III: Special Resource Groundwater
Section 620.240 Class IV: Other Groundwater
Section 620.250 Groundwater Management Zone
Section 620.260 Reclassification of Groundwater by Adjusted Standard

SUBPART C: NONDEGRADATION PROVISIONS FOR APPROPRIATE GROUNDWATERS

Section 620.301 General Prohibition Against Use Impairment of Resource Groundwater
Section 620.302 Applicability of Preventive Notification and Preventive Response Activities
Section 620.305 Preventive Notification Procedures
Section 620.310 Preventive Response Activities

SUBPART D: GROUNDWATER QUALITY STANDARDS

Section 620.401 Applicability
Section 620.405 General Prohibitions Against Violations of Groundwater Quality Standards
Section 620.410 Groundwater Quality Standards for Class I: Potable Resource Groundwater
Section 620.420 Groundwater Quality Standards for Class II: General Resource Groundwater
Section 620.430 Groundwater Quality Standards for Class III: Special Resource Groundwater
Section 620.440 Groundwater Quality Standards for Class IV: Other Groundwater
Section 620.450 Alternative Groundwater Quality Standards

SUBPART E: GROUNDWATER MONITORING AND ANALYTICAL PROCEDURES

Section 620.505 Compliance Determination
Section 620.510 Monitoring and Analytical Requirements

SUBPART F: HEALTH ADVISORIES

Section 620.601 Purpose of a Health Advisory
Section 620.605 Issuance of a Health Advisory
Section 620.610 Publishing Health Advisories
Section 620.615 Additional Health Advice for Mixtures of Similar-Acting Substances

Section 620.APPENDIX A Procedures for Determining Human Toxicant Advisory Concentrations for Class I: Potable Resource Groundwater

Section 620.APPENDIX A Procedures for Determining Human Toxicant Advisory Concentrations for Class I: Potable Resource Groundwater
Section 620.APPENDIX B Procedures for Determining Hazard Indices for Class I: Potable Resource Groundwater for Mixtures of Similar-Acting Substances
Section 620.APPENDIX C Guidelines for Determining When Dose Addition of Similar-Acting Substances in Class I: Potable Resource Groundwaters is Appropriate
Section 620.APPENDIX D Information Required for Groundwater Management Zone Application under 35 Ill. Adm. Code 620.250(b) and Corrective Action Completion Certification under 35 Ill. Adm. Code 620.250(d)
Section 620.APPENDIX E Similar-Acting Substances
AUTHORITY: Implementing and authorized by Section 8 of the Illinois Groundwater Protection Act [415 ILCS 55/8] and authorized by Section 27 of the Illinois Environmental Protection Act [415 ILCS 5/27].
SOURCE: Adopted in R89-14(B) at 15 Ill. Reg. 17614, effective November 25, 1991; amended in R89-14(C) at 16 Ill. Reg. 14667, effective September 11, 1992; amended in R93-27 at 18 Ill. Reg. 14084, effective August 24, 1994; amended in R96-18 at 21 Ill. Reg. 6518, effective May 8, 1997; amended in R97-11 at 21 Ill. Reg. 7869, effective July 1, 1997; amended in R01-14 at 26 Ill. Reg. 2662, effective February 5, 2002; amended in R08-18 at 36 Ill. Reg. 15206, effective October 5, 2012; amended in R08-18(B) at 37 Ill. Reg. 16529, effective October 7, 2013; amended in R22-18 at 49 Ill. Reg. 4488, effective March 28, 2025; amended in R25-23 at 49 Ill. Reg. 12696, effective September 23, 2025.