What are TMDLs?

What are TMDLs?

Total Maximum Daily Loads (TMDLs) are water body pollution reports. A TMDL represents the maximum amount of a pollutant that can enter a water body so that the water body will meet and continue to meet state water quality standards. Section 303(d) of the Clean Water Act requires states to identify all waters that are not meeting their water quality standards. For these waters, the state must calculate how much of a pollutant can be put in the water without violating the standard. That quantity is the total amount of the pollutant from point sources plus the nonpoint sources plus a safety factor to maintain the integrity of the water. TMDLs serve as planning tools for developing specific controls needed to meet water quality standards.