Total Maximum Daily Loads

NRCS scientist and farmer working with nutrient management software.

This page contains introductory information regarding total maximum daily loads (TMDLs). A TMDL serves as a planning tool and potential starting point for restoration or protection activities with the ultimate goal of attaining or maintaining water quality standards

Total Maximum Daily Load Research
USDA. National Agricultural Library.

View dynamic search results from NAL databases for TMDL-related citations.

PubAg:  Articles  |  AGRICOLA:  Books


Implementation: What Happens after the TMDL (Total Maximum Daily Load) is Developed?
Virginia Cooperative Extension.

To translate reductions specified in the TMDL into changes in the watershed, a TMDL Implementation Plan (IP) is developed. This is the next step in the process of restoring water quality.


Assessing the TMDL Approach to Water Quality Management
National Academies Press.

Report focuses on how scientific data and information should be used within the TMDL program.


Evaluating Options for Documenting Incremental Improvement of Impaired Waters under the TMDL Program
Environmental Protection Agency.

Offers working examples of detecting and quantifying incremental improvement of impaired waters and summarizes key TMDL concepts and methods in a consistent framework.


Unleashing the Clean Water Act: The Promise and Challenge of the TMDL Approach to Water Quality
Resources for the Future.

Provides a brief, but thorough, introduction to the implementation of TMDL rules.


The Assessment, Total Maximum Daily Load (TMDL) Tracking and Implementation System (ATTAINS)
Environmental Protection Agency."The Clean Water Act requires states, territories and authorized tribes (states for brevity) to monitor water pollution and report to EPA every two years on the waters they have evaluated. This process is called assessment. Part of this process is deciding which waters do not meet water quality standards because they are too polluted. These degraded waters are called impaired (polluted enough to require action) and are placed on a State list for future actions to reduce pollution." This site includes an interactive Water Quality Assessment and TMDL Information tool.


Water Quality Assessment and TMDL Information
“This site provides information reported by the states to EPA about the conditions in their surface waters. This information is required every two years under Clean Water Act Sections 305(b) and 303(d).

Impaired Waters and Total Maximum Daily Loads Program
Environmental Protection Agency.
Includes access to the documents, Approach for Using Load Duration Curves in the Development of TMDLs (PDF | 3.3MB) and Twenty Needs Report: How Research Can Improve the TMDL Program (PDF | 1.1MB). Also provides links to EPA Regional TMDL Web sites.


Overview of Impaired Waters and Total Maximum Daily Loads Program
Environmental Protection Agency.

Describes the water-quality based approach to protecting and restoring the nation's waters. The TMDL program is designed to achieve the desired uses of a water and may ultimately result in more stringent ...permit limits. 


California Total Maximum Daily Load (TMDL) Program
California State Water Resources Control Board.

Describes and lists TMDL efforts statewide in California.


Illinois Total Maximum Daily Loads (TMDL) Program
Illinois Environmental Protection Agency.

Find regular updates from IEPA containing guidance for meetings, projects implementations, program management, reporting, listing (of impaired waters), development of the water quality tools, and restoration efforts. 


Texas Total Maximum Daily Load (TMDL) Program
Texas Natural Resource Conservation Commission; Texas Institute for Applied Environmental Research; Texas A&M University System.

Information about TMDL programs in Texas.

303(d) Listing and TMDL Information Expert Query
Environmental Protection Agency.
Search National Total Maximum Daily Load (TMDL) Tracking System (NTTS) and TMDL information. AskWATERS can generate cross-program calculations, examines spatial relationships between programs, performs nationwide analyses, produces multi-program inventory reports for a given geographic area, and investigates interstate water quality issues.

TMDL Final Rule
Environmental Protection Agency.
Provides the text of the Jul 13, 2000 Federal Register notice that contains the total maximum daily load final rule. See also the final rule fact sheet (PDF | 25 KB).


Clean Water Act
National Agricultural Law Center.
The Clean Water Act "provides a comprehensive system for the regulation of pollutants in the waters of the United States with the objective of restoring and maintaining the chemical, physical, and biological integrity of the nation’s waters." See also the Environmental Protection Agency's Statute and Regulations addressing Impaired Waters and TMDLs.