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Water: Basics

Watershed-Based NPDES Permitting


Watershed-based NPDES permitting is a process that emphasizes addressing all stressors within a hydrologically-defined drainage basin, rather than addressing individual pollutant sources on a discharge-by-discharge basis. Watershed-based permitting can encompass a variety of activities ranging from synchronizing permits within a basin to developing water quality-based effluent limits using a multiple discharger modeling analysis. The type of permitting activity will vary depending on the unique characteristics of the watershed and the sources of pollution impacting it.  The ultimate goal of this effort is to develop and issue NPDES permits that better protect entire watersheds.  EPA's Water Quality Trading Policy describes flexible approaches to meeting water quality requirements.

This web site provides information related to the development and implementation of NPDES watershed-based permitting approaches.

Policies and Guidance

  • Watershed-Based National Pollutant Discharge Elimination System (NPDES) Permitting Technical Guidance  
    This technical guidance is a follow up to the 2003 Watershed-based National Pollutant Discharge Elimination System (NPDES) Permitting Implementation Guidance and provides greater detail concerning a number of permit development and issuance questions not addressed previously.  This document is focused on helping NPDES authorities develop and issue NPDES permits that fit into an overall watershed planning and management approach with input from watershed stakeholders.   

    EPA is encouraging stakeholders to use this technical guidance and other tools available as a framework  to move watershed-based permitting from the concept to implementation stage.  EPA is seeking comments and feedback on the technical guidance as permitting authorities and other stakeholders use it.  Please send all comments to EPA's Watershed Permitting Team.
          Date Published: 07/20/2007  

  • Watershed-Based NPDES Permitting Case Studies  
    To promote the innovative watershed-based permitting approach, EPA has generated a case study fact sheet series that presents an overview of watershed-based permitting efforts.  Note: EPA regularly updates these fact sheets to reflect the most current progress and results in watershed-based permitting.
      Date Published: 12/17/2003  
  • Watershed-Based National Pollutant Discharge Elimination System (NPDES) Permitting Implementation Guidance  
    Describes EPA's recommended steps and ideas for watershed-based permitting implementation under the National Pollutant Discharge Elimination System (NPDES) permit program. This approach, aimed at achieving new efficiencies and environmental results, provides a process for considering all stressors within a hydrologically defined drainage basin or other geographic area, rather than addressing individual pollutant sources on a discharge-by-discharge basis (EPA 833-B-03-004).
      Date Published: 12/17/2003  
  • Memorandum: Watershed-Based NPDES Permitting Policy Statement  
    Describes the benefits of watershed-based permitting, the implementing mechanisms for this component of the watershed approach, and how EPA will be encouraging use of watershed-based NPDES permits.
      Date Published: 01/07/2003  
  • Committing EPA's Water Program to Advancing the Watershed Approach - Memo from the Assistant Administrator for Water, G. Tracy Mehan, III, on December 3, 2002.

Background Information

  • Watershed-Based NPDES Permitting: Rethinking Permitting As Usual  
    Brochure defines watershed-based NPDES permitting, including potential approaches and benefits.  Also provides examples of watershed-based permitting happening around the country and EPA's efforts to promote this approach.
      Date Published: 05/01/2003  
  • Watershed-Based Permitting Under the NPDES Program: A Summary of Related Background Information  
    Provides a compilation and summary of background information relevant to watershed-based permitting.
      Date Published: 09/30/2002  
  • Potential Partners in Promoting Watershed-based Permitting: An Analysis of Watershed Organizations  
    Provides a cross-sectional analysis of successful organizations engaged in watershed management.  As described in the report, EPA analyzed 29 selected organizations in 17 states for potential that these organizations may have to play a role in implementing watershed-based NPDES permitting based on their current goals and activities.
      Date Published: 09/30/2002  

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