Impaired Waters 303(d) Listings

The term "303(d) list" is short for the list of impaired and threatened waters (e.g., stream/river segments, lakes) that have been identified and reported to EPA. The Clean Water Act (CWA) requires states, territories, and authorized tribes to submit impaired waters lists for EPA approval by April 1 of even-numbered years. For more information on how states identify impaired waters, submit lists, and report on water quality through an integrated reporting procedure, see Overview of Impaired Waters and Total Maximum Daily Loads Program. The listing process has led to the identification and tracking of over 40,000 impaired waters nationally. This page summarizes progress on national listing efforts with EPA Regional and jurisdiction-specific summaries, maps of reporting status, and more resources of interest.

In recent years, states and EPA have worked together to improve the timeliness of this reporting through issuance of guidance (e.g., 2006 Integrated Report Guidance). EPA also developed the Assessment and TMDL Tracking and Implementation System (ATTAINS), an online database that provides integrated state-reported information on water quality assessments, impaired waters and TMDLs to the public. Impaired waters list information is available in tabular form through ATTAINS, as well as in mapped form available as downloadable Geographic Information System (GIS) files.

Resources of Interest

You will need Adobe Reader to view some of the files on this page. See EPA's PDF page to learn more.

• Fact Sheet: Introduction to Clean Water Act Section 303(d) Impaired Waters Lists (PDF) (2pp, 93K), July 2009
  This fact sheet overviews the impaired waters 303(d) listing process for states, territories, and authorized tribes.
• Fact Sheet: Status of 303(d) Impaired Waters List Submissions to EPA (PDF) (1pp, 87K), July 2009
  This fact sheet provides the status of biennial state impaired waters list submissions to EPA.
• Fact Sheet: Integrated Reporting (IR) – Improved Reporting for CWA Sections 303(d), 305(b), and 314 (PDF) (2pp, 341K), July 2009
  This fact sheet summarizes integrated reporting and the status of state integrated report submissions to EPA.
• Fact Sheet: Recovery Potential Project (PDF) (2pp, 243K), May 2011
  This fact sheet overviews tools, data and a website developed by EPA to help state TMDL, nonpoint source, and restoration programs decide where best to use their limited restoration resources among large numbers of impaired waters.
  
• Fact Sheet: 2002 Impaired Waters Baseline National Geospatial Dataset (PDF) (2pp, 133K), December 2009
  This fact sheet describes a publicly available GIS dataset of the impaired waters national baseline of 2002, a major tracking and national performance reporting reference date for EPA.
• Dataset: 2002 Impaired Waters Baseline National Geospatial Dataset
  This publicly available GIS dataset contains the impaired waters national baseline of 2002, a major tracking and national performance reporting reference date for EPA.
• Dataset: National Summary of Impaired Waters in ATTAINS Database
  This online database provides dynamic, continuously updated national information on impaired waters listed by state, approved TMDLs by state and pollutant, and status of available data used in this report.
• Fact Sheet: 303(d) Listed Impaired Waters State, Watershed and National Geospatial Datasets (PDF) (2pp, 474K), January 2010
  This fact sheet describes the most recent publicly available GIS data on 303(d) listed impaired waters, available at watershed, state or national scale. Dates vary by state.
• Dataset: Section 303(d) Listed Impaired Waters State or Watershed-level, Geographic Information Systems (GIS) Data Downloads
  This website is a source for obtaining the most up-to-date, GIS data files of 303(d)-listed impaired waters on a state or watershed-specific basis from EPA’s Reach Address Database (RAD).
• Dataset: Section 303(d) Listed Impaired Waters National Geospatial Dataset
  This website is a source for obtaining a national, geospatial coverage of 303(d) listed impaired waters.
• Fact Sheet: Watershed Boundaries for the 2002 Impaired Waters Baseline National Geospatial Dataset (PDF) (2pp, 245K), December 2009
  This fact sheet describes a publicly available GIS dataset consisting of the watershed boundary delineations for the impaired waters national baseline of impaired waters through reporting year 2002, a major tracking and national performance reporting reference date for EPA.
• Dataset: Watershed Boundaries for the 2002 Impaired Waters Baseline National Geospatial Dataset
  This website is a source for obtaining a national, geospatial coverage of watershed boundaries for the 2002 impaired waters baseline, a major tracking and national performance reporting reference date for EPA.
• EPA website: STORET/WQX Database Access
  EPA maintains two data warehouse systems containing water quality information for the nation's waters: the Legacy Data Center (LDC), and the STOrage and RETrieval warehouse (STORET). The LDC is a static, archived database and STORET is an operational system actively being populated with water quality data through the Water Quality Exchange (WQX).

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