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  2. National Pollutant Discharge Elimination System (NPDES)
  3. About NPDES

NPDES Regulations

Regulations of Other NPDES Program Areas
  • Animal feeding operations
  • National pretreatment program
  • Pesticide applications
  • Stormwater
  • Vessels incidental discharge permitting

EPA originally published the general NPDES regulations at Title 40 of the Code of Federal Regulations (CFR) in 1972. The primary regulations developed by EPA to implement and administer the NPDES permit program are:

  • Part 122: EPA-Administered Permit Programs: The National Pollutant Discharge Elimination System
  • Part 123: State Program Requirements
  • Part 124: Procedures for Decisionmaking
  • Part 125: Criteria and Standards for the National Pollutant Discharge Elimination System

Other important regulations applicable to the NPDES program are:

  • Part 127: NPDES Electronic Reporting
  • Part 133: Secondary Treatment Regulation
  • Part 403: General Pretreatment Regulations for Existing and New Sources of Pollution
  • Part 501: State Sludge Management Program Regulations
  • Part 503: Standards for the Use or Disposal of Sewage Sludge

2019

Notice and Request for Comment: Trading Baselines

On September 5, 2019, EPA invited the public to consider and comment on policy options that may help promote market-based approaches to water quality improvements.

  • Federal Register Notice, September 19, 2019 (PDF)(5 pp, 132 K, About PDF)

2018

Final Rule: National Pollutant Discharge Elimination System (NPDES): Applications and Program Updates (Phase 1)

This final rule addresses a subset of the revisions proposed in 2016, modernizes the NPDES regulations, and promotes submission of complete permit applications.

  • Federal Register Notice, February 12, 2019 (PDF)(15 pp, 326 K, About PDF)

Final Rule: Public Notification for CSOs to the Great Lakes

The January 8, 2018, rule implements Section 425 of the Consolidated Appropriations Act of 2016, which requires EPA to work with the Great Lakes States to establish public notification requirements for combined sewer discharges (CSOs) to the Great Lakes. The requirements address signage, initial notification of local public health departments and other potentially affected entities, initial notification of the public, annual notice provisions, and development of a public notification plan.

  • Federal Register Notice, January 8, 2018 (PDF)(21 pp, 1.1 MB, About PDF)

2015

Final Rule: NPDES Electronic Reporting

This final rule substitutes electronic reporting for paper-based reports. It requires permittees and regulators to use existing, available information technology to electronically report information and data related to the NPDES permit program in lieu of filing paper-based reports.

  • Federal Register Notice, October 22, 2015 (PDF)(96 pp, 1 MB, About PDF)

2014

National Pollutant Discharge Elimination System (NPDES): Use of Sufficiently Sensitive Test Methods for Permit Applications and Reporting

EPA finalized minor amendments to the NPDES regulations to require that its Clean Water Act (CWA) regulations to codify that under the NPDES program, only "sufficiently sensitive" analytical test methods may can be used when completing an NPDES permit application and when performing sampling and analysis pursuant to monitoring requirements in an NPDES permit. 

  • Federal Register Notice, September 18, 2014 (PDF)(13 pp, 282 KB, About PDF)
  • Fact Sheet

Final Rule: Cooling Water Intakes – Existing Electric Generating Plants and Factories

This August 15, 2014, final rule covers roughly 1,065 existing facilities that are designed to withdraw at least 2 million gallons per day of cooling water. The facilities are required to choose one of seven options to reduce mortality to fish and other aquatic organisms. Facilities that withdraw at least 125 million gallons per day must conduct studies to help their permitting authority determine whether and what site-specific controls, if any, would be required to further reduce mortality of aquatic organisms. New units added to an existing facility are required to reduce mortality of aquatic organisms that achieves one of two alternatives under national entrainment standards.

  • Federal Register Notice, August 15, 2014 (PDF)(141 pp, 1 MB, About PDF)

National Pollutant Discharge Elimination System (NPDES)

  • About NPDES
    • Permit Basics
    • State Program Information
    • Permit Limits
    • Program Management and Oversight
    • NPDES Regulations
    • Other Federal Laws that Apply to the NPDES Permit Program
  • All NPDES Program Areas
    • Animal Feeding Operations
    • Aquaculture
    • Forest Roads
    • Industrial Wastewater
    • Municipal Wastewater
      • Combined Sewer Overflows (CSOs)
      • Sanitary Sewer Overflows (SSOs)
      • Peak Flows
      • Integrated Planning
    • National Pretreatment Program
      • Standards and Requirements
      • Roles and Responsibilities
      • Events, Training and Webinars, and Publications
    • Pesticide Permitting
    • Stormwater
      • Construction Activities
      • Industrial Activities
      • Municipal Sources
      • Transportation Sources
      • Oil and Gas Permitting
      • Stormwater Planning
      • EPA's Residual Designation Authority
      • Rules and Notices
    • Water Quality Trading
  • NPDES Technical Resources
    • Resources for Permit Writers
    • NPDES Permit Writers' Manual
    • NPDES Training
    • Tools
    • Electronic Notice of Intent (eNOI)
    • NPDES Applications and Forms
Contact Us About NPDES
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 10, 2025
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