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Clean Water Act Section 303(d): Impaired Waters and Total Maximum Daily Loads (TMDLs)

  • Identifying Polluted Waters and Developing Plans to Restore Them

    Learn about Section 303(d) of the Clean Water Act.

Section 303(d) of the Clean Water Act authorizes EPA to assist states, territories and authorized tribes in listing impaired waters and developing Total Maximum Daily Loads (TMDLs) for these waterbodies. A TMDL establishes the maximum amount of a pollutant allowed in a waterbody and serves as the starting point or planning tool for restoring water quality.

Highlights

  • 2022 - 2032 Vision for the Clean Water Act Section 303(d) Program
  • Information Concerning 2022 Clean Water Act Sections 303(d), 305(b) and 314 Integrated Reporting and Listing Decisions

About the Program

  • Water Restoration and Protection in the U.S.
    • Impaired Waters Restoration Process
    • Healthy Watersheds
  • Program Overview
    • Section 303(d) of the CWA
    • Listing Impaired Waters
    • TMDLs
  • What You Can Do

Program Activities in EPA's Regions

  • Find Your Region
  • Find Impaired Waters in Your State using the Assessment and TMDL Tracking System (ATTAINS)

Working with the States

  • Statute and Regulations
  • National Coordination
  • Program Vision
  • Identifying and Listing Impaired Waters
  • Developing TMDLs
  • Alternative Restoration Plans
  • Protection Approaches
  • Technical Tools & Resources
  • Assessing Impacts from:
    • Mercury
    • Nutrients
    • Ocean Acidification
    • Stormwater

Partnerships

  • Working with Stakeholders
  • Working with Tribes
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on September 15, 2022
United States Environmental Protection Agency

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