Total Maximum Daily Loads (TMDLs)

The Clean Water Act requires state adoption of water standards for designated uses, such as for drinking water, fishing, protection of aquatic life, swimming, irrigation or industrial purposes. Total Maximum Daily Load (TMDL) studys are to be conducted if water segments/bodies fail to meet one or more standards due to pollutants such as nutrients and pesticides. A TMDL study identifies both point and nonpoint sources of pollutants and uses monitoring and computer modeling to determine how much each pollutant source must reduce its contribution to assure the water quality standard is met.

Voluntary programs and existing federal, state, and local authorities can be used to implement TMDLs. A Region 7 EPA web site further summarizes the TMDL issues for the Heartland Region. State administered TMDL programs are also Web accessible (Kansas, Nebraska, Iowa, Missouri).