Antidegradation

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

Antidegradation Background & Additional References

• Introduction to Antidegradation  
• Iowa Antidegradation Implementation Procedure (2-17-10) 
• Antidegradation and Permitting Scenarios in Iowa 
• Frequently Asked Questions, Degradation/No Degradation Scenarios 
• EPA Interim Economic Guidance for Water Quality Standards

Antidegradation Forms & Information

• Exhibit 9A - Preliminary Review of Antidegradation Alternatives Analysis 
• Affordability Analysis for Communities, Financial Worksheet - Blank Form
• Affordability Analysis for Communities, Sample Public Notice
• Public and Interagency Contact List - Google Sheet

Example Alternative Analyses & Financial Worksheets

• Example Alternative Analysis for a Municipal Wastewater Facility
• Financial Worksheet - Completed Example
• Example Alternative Analysis for Cooling Tower Chemical Switch
• Example Alternative Analysis for a New Industrial Contributor to a Municipal WWTP

Other Forms & Information

• Exhibit 3 - Waste Load Allocation Request Form and Instructions
• Outstanding Iowa Waters Map

Outstanding Iowa Waters (OIWs)

Printable maps of the locations of Iowa’s Outstanding Iowa Waters (OIWs) are offered for download. For more detailed information about each specific stream, browse and download the individual OIW Maps.