What does the CWA define "Effluent limitation" as?

The term "effluent limitation" under the Clean Water Act (CWA) specifically refers to restrictions placed on the levels of pollutants that can be discharged from point sources into navigable waters, which include oceans, rivers, and other bodies of water. This definition is anchored in the CWA’s objective to restore and maintain the integrity of the nation's waters by regulating discharges of pollutants. The emphasis is on point sources, which are identifiable and concentrated sources of pollution, such as industrial facilities and sewage treatment plants, as opposed to non-point sources like agricultural runoff or atmospheric deposition.

Effluent limitations are established to ensure that these point sources do not contribute harmful levels of pollutants, thereby safeguarding water quality and ecosystem health. Through permits issued under the National Pollutant Discharge Elimination System (NPDES), specific, quantifiable limits can be set for various pollutants, which are then legally enforceable. Thus, the definition relating to point sources is fundamental to understanding the regulatory framework intended to protect water resources under the CWA.