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Water Quality Standards Regulations: Illinois

Presented below are water quality standards in effect for Clean Water Act (CWA) purposes for this state.

The EPA is posting these standards as a convenience to users and has made a reasonable effort to assure their accuracy. Also, for each document listed under "State Standards in Effect for CWA Purposes", the EPA has made a reasonable effort to identify parts of the standards that are disapproved or are otherwise not in effect for CWA purposes.

On this page:

State Standards in Effect for CWA Purposes

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Federally Proposed or Promulgated Standards

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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.

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