• State Standards in Effect for CWA Purposes
• Federally Proposed or Promulgated Standards
• Federal Clean Water Act Determinations that New or Revised Standards Are Necessary

State Standards in Effect for CWA Purposes

• [See Introduction - Title 35: Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 301 ]
  (Effective May 28, 2013) Document contains statements of authority, policy, and definitions relative to the Illinois water quality standards. Please note that not all provisions are in effect for Clean Water Act purposes. See the document cover page for more information.
  • [See Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 301 (1999) ]
    (Effective August 26, 1999)
• [See Water Quality Standards - Title 35: Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 302 ]
  (Effective June 24, 2019) Document contains general provisions of the Illinois water quality standards.
• Derived Water Quality Criteria Exit
  These water quality criteria are derived from EPA-approved methodologies contained in Illinois' water quality standards at Section 302, Subpart F ("Procedures for Determining Water Quality Criteria"). The criteria themselves are not submitted to EPA for approval but are a numeric expression of Illinois' approved narrative criterion and translator.
• [See Use Designations and Site Specific Water Quality Standards - Title 35: Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 303 ]
  (Effective June 24, 2019) Water use designations and site-specific water quality standards. Please note that not all provisions are in effect for Clean Water Act purposes. See cover page for more information.
• [See Antidegradation Provisions for Bioaccumulative Chemicals of Concern – Title 35: Environmental Protection, Chapter II: Environmental Protection Agency, Part 352.900 ]
  Antidegradation Provisions from Section 352.90.
• [See Effluent Disinfection Exemptions - Title 35: Environmental Protection, Subtitle C: Water Pollution, Chapter 1: Pollution Control Board, Part 378 ]
  Document establishes requirements for determining which National Pollutant Discharge Elimination System permit dischargers may cease effluent disinfection on seasonal or year-round basis.
• [See Illinois Permitting Guidance for Mixing Zones ]
  (March 15, 1993) Note: Illinois has decided not to adopt requirements governing the development of total maximum daily loads for the Great Lakes System consistent with the requirements in Procedure 3 in Appendix F in the Great Lakes Guidance contained at 40 CFR 132. Pursuant to the Great Lakes Guidance, EPA has determined that the federal provisions at 40 CFR 132, Appendix F, Procedure 3 shall apply.

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Federally Proposed or Promulgated Standards

• 40 CFR §131.41  Bacteriological criteria for those states not complying with Clean Water Act section 303(i)(1)(A)
• 40 CFR § 132  Water Quality Guidance for the Great Lakes System

Federal Clean Water Act Determinations that New or Revised Standards Are Necessary

EPA has issued the following determinations under Clean Water Act section 303(c)(4)(B) that new or revised standards are necessary. EPA may propose federal replacement standards in these cases if the state does not adopt standards consistent with the Act.

• Determination that New Water Quality Standards are Necessary to Protect Segments of the Chicago Area Waterway System (CAWS) for Recreation
  • [See Determination Letter ] (signed May 11, 2011)

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• Introduction - Title 35: Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 301 (PDF)(29 pp, 211 K)
• Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 301 (1999) (PDF)(21 pp, 87 K)
• Antidegradation Provisions for Bioaccumulative Chemicals of Concern – Title 35: Environmental Protection, Chapter II: Environmental Protection Agency, Part 352.900 (PDF)(25 pp, 97 K)
• Effluent Disinfection Exemptions - Title 35: Environmental Protection, Subtitle C: Water Pollution, Chapter 1: Pollution Control Board, Part 378 (PDF)(13 pp, 71 K)
• Illinois Permitting Guidance for Mixing Zones (PDF)(18 pp, 1 MB)
• Determination Letter (PDF)(9 pp, 528 K)
• Water Quality Standards - Title 35: Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 302 (PDF)(194 pp, 859 K)
• Use Designations and Site Specific Water Quality Standards - Title 35: Environmental Protection, Subtitle C: Pollution, Chapter 1: Pollution Control Board, Part 303 (PDF)(24 pp, 395 K)