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Antidegradation refers to federal regulations designed to maintain and protect high quality waters and existing water quality in other waters from unnecessary pollution.

Proposed revisions to the Iowa Antidegradation Procedure
The Environmental Protection Commission and the Department of Natural Resources received a Petition for Rulemaking from the Iowa Association of Municipal Utilities, the Iowa League of Cities, and the Iowa Association of Business and Industry on April 25, 2016.  The following documents are related to that Petition and the resulting rulemaking:

Petition for Rulemaking
Notice of Intended Action – Proposed revisions to Chapters 61 and 64
Final Rule – Proposed Revisions to Chapters 61 and 64
Responsiveness Summary for Proposed Revisions to Chapters 61 and 64
Proposed Revised Iowa Antidegradation Implementation Procedure (Final with markup)
Proposed Revised Iowa Antidegradation Implementation Procedure (Final without markup)

Background and Additional Reference
Introduction to Antidegradation  
Iowa Antidegradation Implementation Procedure (2-17-10) 
List of Scenarios  
Frequently Asked Questions  
EPA Interim Economic Guidance for Water Quality Standards  

Antidegradation Forms and Information


Questions? Contact:
Larry Bryant, larry.bryant@dnr.iowa.gov; 515-725-8426
Roger Bruner, roger.bruner@dnr.iowa.gov; 310-0247-8400

Outstanding Iowa Waters
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