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 of this provision has been dormant until recently, when states and EPA were prodded by numerous lawsuits. The TMDL issue has become controversial, in part because of requirements and costs now facing states to implement a 25-year-old provision of the law. Congressional activity to reauthorize the Act, a possibility in the 2nd Session of the 105th Congress, could include TMDL issues, but the direction for any such action is unclear at this time.