Clean Water Act and Total Maximum Daily Loads (TMDLs) of Pollutants

Section 303(d) of the Clean Water Act requires states to identify waters that are impaired by pollution, even after application of pollution controls. For those waters, states must establish a total maximum daily load (TMDL) of pollutants to ensure that water quality standards can be attained. Implementation was dormant until recently, when states and EPA were prodded by numerous lawsuits