Water Quality Standards Regulations: Iowa

Presented 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. 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. Additionally, please note the documents may also contain provisions that the EPA does not have the authority and duty to act on under the Clean Water Act because the provisions are not water quality standards.

• What is a New or Revised Water Quality Standard Under CWA 303(c)(3)? - Frequently Asked Questions (pdf) (108.04 KB)

• State Standards in Effect for CWA Purposes
• Federally Proposed or Promulgated Standards

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State Standards in Effect for CWA Purposes

• Section 1: Title IV, Chapter 60, Wastewater Treatment and Disposal (pdf) (995.95 KB)
• Section 2: Chapter 61, Water Quality Standards (2022) (pdf) (348.61 KB)
  (Effective February 2, 2022) Surface water quality standards for waters of the state.  Please note that not all provisions are effective for Clean Water Act purposes (refer to cover page for more information).
• Surface Water Classifications (pdf) (4.67 MB)
  (Effective September 29, 2020)
• Section 3: Modifications to Chapter IV - Basin Plan Support Document (pdf) (3.22 MB)
• Iowa Antidegradation Implementation Procedure (pdf) (225.86 KB, February 17, 2010)

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Federally Proposed or Promulgated Standards

• None at this time.