Water Quality
Module 3

Lesson 1- Total Maximum Daily Loads (TMDLs), Information Sheet
Acknowledgement: Taken from "Living on the Land 2001"

The Total Maximum Daily Load Program

More than 40 percent of assessed waters in the United States still do not meet the water quality standards states, territories, and authorized tribes have set for them. This amounts to more than 20,000 individual river segments, lakes, and estuaries. These impaired waters include approximately 300,000 miles of rivers and shorelines and approximately 5 million acres of lakes – polluted mostly by sediments, excess nutrients, and harmful microorganisms. An overwhelming majority of U.S. citizens – 218 million people – live within 10 miles of an impaired waterway.

Under section 303(d) of the 1972 Clean Water Act, states, territories, and authorized tribes are required to develop lists of impaired waters. These impaired waters do not meet at least one of the water quality standards that states, territories, and authorized tribes have set for them, even after point sources of pollution have installed the minimum required levels of pollution control technology. The law requires that these jurisdictions establish priority rankings for waters on the lists and develop Total Daily Maximum Loads (TMDLs) for these waters.

What is a Total Daily Maximum Load (TMDL)?

A TMDL specifies the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and allocates pollutant loadings among point and nonpoint pollutant sources. By law, the Environmental Protection Agency (EPA) must approve or disapprove lists of impaired waters and TMDLs established by states, territories, and authorized tribes. If a state, territory, or authorized tribe submission is inadequate, EPA must establish the list or the TMDL. EPA issued regulations in 1985 and 1992 that implement section 303(d) of the Clean Water Act – the TMDL provisions.

While TMDLs have been required by the Clean Water Act since 1972, until recently states, territories, authorized tribes, and the EPA have not developed many. Several years ago citizen organizations began bringing legal actions against the EPA, seeking the listing of waters and development of TMDLs. To date, there have been about 40 legal actions in 38 states. The EPA is under court order or consent decrees in many states to ensure that TMDLs are established, either by the state or by the EPA.

EPA Actions to Implement the TMDL Program

In an effort to speed the Nation’s progress toward achieving water quality standards and improving the TMDL program, the EPA began, in 1996, a comprehensive evaluation of the EPA’s and the states’ implementation of their Clean Water Act section 303(d) responsibilities. The EPA convened a committee under the Federal Advisory Committee Act, composed of 20 individuals with diverse backgrounds, including agriculture, forestry, environmental advocacy, industry, and state, local, and tribal governments. The committee issued its recommendations in 1998.

These recommendations were used to guide the development of proposed changes to the TMDL regulations, which the EPA issued in draft in August, 1999. After a long comment period, hundreds of meetings and conference calls, much debate, and the Agency’s review and serious consideration of more than 34,000 comments, the final rule was published on July 13, 2000, prompting legal challenges by more than two dozen parties. On July 16, 2001, EPA Administrator Christie Whitman asked the court to stay the litigation to correspond with the EPA’s plan to propose an 18-month extension of the effective date of the rule while the agency reviews and revises the rule to achieve a program that is workable and meets the goal of clean water. The existing TMDL program will continue to be enforced during this review period.

See http://www.epa.gov/owow/tmdl/ for more information on TMDLs.

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