Jump to main content.


What are Water Quality Standards?

[Why are WQS Important?] [WQS Review and Revision] [Role of the Public] [Designated Uses] [Water Quality Criteria] [Antidegradation] [General Policies] [Indian Tribe Participation] [WQS Program History]

Why Are Water Quality Standards Important?

Water quality standards are important because they help to protect and restore the quality of the Nation's surface waters, consistent with the requirements of the Clean Water Act. Standards help to identify water quality problems caused by, for example, improperly treated wastewater discharges, runoff or discharges from active or abandoned mining sites, sediment, fertilizers, and chemicals from agricultural areas, and erosion of stream banks caused by improper grazing practices. Standards also support efforts to achieve and maintain protective water quality conditions, including:

  1. total maximum daily loads (TMDLs), waste load allocations (WLAs) for point sources of pollution, and load allocations (LAs) for non point sources of pollution,
  2. water quality management plans which prescribe the regulatory, construction, and management activities necessary to meet the water body goals,
  3. NPDES water quality-based effluent limitations for point source discharges,
  4. water quality certifications under CWA §401 for activities that may affect water quality and that require a federal license or permit,
  5. reports, such as the reports required under CWA §305(b), that document current water quality conditions, and
  6. CWA §319 management plans for the control of non point sources of pollution.

Models | TMDLs | Permits | Water Quality Criteria | Monitoring


Local Navigation


Jump to main content.