TMDLS:WHAT ARE THEY, AND HOW WILL THEY IMPACT YOU?

Authors: Bosch, David - Dave

Submitted to: American Society of Agricultural Engineers Resource Magazine
Publication Type: Review Article
Publication Acceptance Date: 1/3/2003
Publication Date: 1/3/2003
Citation: BOSCH, D.D. TMDLS:WHAT ARE THEY, AND HOW WILL THEY IMPACT YOU?. AMERICAN SOCIETY OF AGRICULTURAL ENGINEERS RESOURCE MAGAZINE.10(1):13-17. 10(3):11-12. 2003.

Interpretive Summary: Since passage of the Clean Water Act in 1972, significant strides have been made to clean up our Nation's waterbodies. Despite this progress, over 40% of the waters which have been assessed in the U.S. still do not meet the set water quality standards. These waters amount to over 20,000 individual river segments, lakes, and estuaries, including nearly a half million km of rivers and shorelines and approximately 2 million ha of lakes. Litigation surrounding the intent of the Clean Water Act has forced the EPA and states to implement programs which identify all waterbodies not meeting their designated uses and make plans to reduce pollutants to levels where the waters would no longer be impaired. A review of this program, commonly referred to as the TMDL program after the establishment of `total maximum daily loads' which are allowable while still meeting the established water quality standards, indicates the complexities impacting the program. While the TMDL program is continually changing, it has forced the Nation to take a serious look at water quality problems throughout the U.S. and to make serious efforts to reducing these problems.

Technical Abstract: Since passage of the Clean Water Act in 1972, significant strides have been made to clean up our Nation's waterbodies. By permitting and regulating point source discharges, the health of many of our Nation's watersheds has been dramatically improved. Despite this progress, over 40% of the waters which have been assessed in the U.S. still do not meet the set water quality standards. These waters amount to over 20,000 individual river segments, lakes, and estuaries, including nearly a half million km of rivers and shorelines and approximately 2 million ha of lakes. Litigation surrounding the intent of the Clean Water Act has forced the EPA and states to implement programs which identify all waterbodies not meeting their designated uses and make plans to reduce pollutants to levels where the waters would no longer be impaired. The program through which this is run is referred to as the TMDL program, after the establishment of `total maximum daily loads' which are allowable while still meeting the established water quality standards. A TMDL is the sum of point and nonpoint sources, natural background, and a margin of safety to ensure the pollutant levels remain below established standard. This report outlines the roles of the EPA and the states in this process. The TMDL program will be a continually evolving process and one that will be extremely costly. It has forced us to take a serious look at the condition of our Nation's waterbodies and the steps necessary to improve their condition.