National Pollutant Discharge Elimination System (NPDES): The NPDES permit program, established under the Clean Water Act, controls water pollution by regulating point sources that discharge pollutants into U.S. waters.
Total Maximum Daily Load (TMDL): A TMDL is the maximum amount of a pollutant that a body of water can receive and still meet water quality standards. It is a key tool used to restore impaired waters under the Clean Water Act.
Water Quality Standards: Water quality standards are the foundation of the water quality-based pollution control program mandated by the Clean Water Act. They define the goals for a water body by designating its uses, setting criteria to protect those uses, and establishing provisions to protect water quality.