EPA Environmental Dataset Gateway


Open/Close section Identification Information
Title: EPA Office of Water (OW): Impaired Waters with TMDLs by Causes of Impairment and Probable Sources and TMDL Pollutant
Abstract: Under Section 303(d) of the Clean Water Act (CWA), states, territories, and authorized tribes, collectively referred to in the Act and here as "states," are required to develop lists of impaired waters. A state’s 303(d) impaired waters list is comprised of all waters where required pollution controls are not sufficient to attain or maintain applicable water quality standards. The law requires that states establish priority rankings for waters on the lists and develop Total Maximum Daily Loads (TMDLs). A TMDL is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of the load reduction needed from various sources of the pollutant.
Purpose: The data can be used to identify the distribution of impaired waters with a TMDL within each state for pollutants of interest. The attribute information provided (e.g., TMDL pollutant, location, waterbody name) can be associated with the geospatial information (TMDLs on Impaired Waters NHD Indexed Dataset found at https://www.epa.gov/waterdata/waters-geospatial-data-downloads). The attribute information can be downloaded at http://watersgeo.epa.gov/GEOSPATIALDOWNLOADS/attgeo_tmdlcaussrcepoll_20150501.xlsx . Please note that a water can be identified on a State’s 303(d) list as impaired for more than one cause of impairment and be identified as having more than one probable source. EPA considers TMDLs as water/pollutant combinations, please be mindful of this information when aggregating the attributes for analysis needs.
Open/Close section Distribution Information
Download URL: https://www.epa.gov/waterdata/waters-geospatial-data-downloads#ImpairedWatersWithTMDLs
Open/Close section Time Period of Content
Publication Date: 20150501
Progress: Completed
Frequency: None Planned
Open/Close section Single Date
Date: 20150501
Currentness: Publication date
Open/Close section Spatial Domain
West Bounding Longitude: -180
East Bounding Longitude: 180
North Bounding Latitude: 90
South Bounding Latitude: -90
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Open/Close section Constraints
License https://edg.epa.gov/EPA_Data_License.htm
Access: None
Use: None. Please check sources, scale, accuracy, currency and other available information. Please confirm that you are using the most recent copy of both data and metadata. Acknowledgement of the EPA would be appreciated.
Open/Close section Theme Keywords
Theme Topics: impaired waters, 303d, TMDL, clean water act, listed waters, total maximum daily loads, TMDLs, CWA, point source, EPA, Stream, reach
Open/Close section Contact Information
Originator: US Environmental Protection Agency, Office of Water
Email: reid.wendy@epa.gov
Address Type: mailing address
City: Washington
State: DC
Postal Code: 20460
Telephone: 202-566-1705
Open/Close section Metadata Reference Information
File Identifier: {FEC21D2C-D1CE-4CC5-A9DA-BDDFABE8ACA5}
Metadata Date Stamp: 2016-08-05
Metadata Standard Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata Standard Version: FGDC-STD-001-1998