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What are Water Quality Standards?

Water quality standards help to protect and restore the quality of our surface waters in accordance with the Clean Water Act (CWA).  Water quality standards define the goals for a waterbody by designating its uses, setting criteria to protect those uses, and establishing provisions to protect water quality from pollutants.  To do this, the South Carolina Department of Health & Environmental Control works with the U.S. Environmental Protection Agency to continually revise existing standards and create new standards based on changing water quality conditions, changing waterbody uses, and/or new scientific information on the effects of pollutants in the environment. 

The CWA requires that each state must review its water quality standards at least once every three years.  This process is known as the triennial review.  The triennial review includes public hearings on water quality standards which provide the public an opportunity to become involved in the water quality standards review process.  Upcoming public input opportunities for the triennial review and other water quality standards activities can be found on our water quality standards public input page.

Water quality standards also support efforts to achieve and maintain protective water quality conditions, such as:

  • Total maximum daily loads (TMDLs)
  • Waste load allocations (WLAs) for point source dischargers
  • Load allocations (LAs) for non-point source dischargers
  • Water quality management plans
  • Effluent limits for NPDES permits
  • Water quality certifications under Section 401 of the CWA
  • State of South Carolina Integrated Report
    • Part I: Listing of Impaired Waters (commonly referred to as the 303(d) list)
    • Part II: Assessment and Reporting (commonly referred to as the 305(b) report)
  • Section 319 non-point source pollution grants