Surface Water Standards

Surface Water Quality Standards

What Are Water Quality Standards?

Water quality standards are state regulations or rules that serve to protect the lakes, rivers, streams, and other surface waters of the state from the deleterious effects of pollution. Surface waters are protected based on their designated "best uses" as defined in the surface water classifications established in Title 15A of the North Carolina Administrative Code (NCAC) subchapter 02B. For more information on surface water classifications, please see the Surface Water Classifications webpage.

The current water quality standards for surface waters can be viewed here in rules 15A NCAC 02B .0100 through .0300 (effective date: November 1, 2019).

Water quality standards are implemented through the issuing of permit limits to facilities with National Pollutant Discharge Elimination (NPDES) permits, the establishment of water quality benchmarks for the Stormwater Permitting Program, and the development of Total Maximum Daily Loads (TMDLs). Water quality standards are also used to determine the "use status" of surface waters. Waters that are meeting their prescribed water quality standards and that have good biological communities are considered to be supporting all of their uses. Waters that are not meeting these requirements may be considered "impaired" and may require further analysis and, possibly, a management strategy.

More information on biological communities can be found on the Biological Assessment Branch website. Information on impaired waters can be found on the 303d Impaired Waters website.

North Carolina's Legal Obligations & Responsibilities

States are required, under the Federal Water Pollution Control Act (Clean Water Act), to review their water quality standards and classifications every three years and to make any modifications necessary to protect the waters of the state. During this process, known as a Triennial Review, DEQ staff review current EPA guidelines, scientific data, and public comments and make recommendations for any changes of the water quality standards to the North Carolina Environmental Management Commission (EMC). Following a stakeholder comment period, public hearings, and fiscal analysis, and upon approval by the EMC, the Triennial Review package goes to the North Carolina Rules Review Commission (RRC) for final approval and adoption into state rule.

Water Quality Standards Tables & Variances

The following water quality standard tables are resources to be used as a reference for looking up water quality standards or criteria for the waters of the state. They do not substitute for any written regulations, nor are they regulations themselves. To use these tables: First, locate the pollutant of interest in the left column. Next, read across the table to the right to find the water quality standard or criteria related to the designated use associated with the water body of interest. If a water body has multiple designated uses, the most protective (i.e. lowest) standard or criteria will be applied.

Triennial Review Information

Documentation related to current and past triennial reviews can be found below.

2020-2022 Triennial Review

Public Notice - Includes information regarding the proposed rulemaking actions for the 2020-2022 Surface Water Standards Triennial Review as well as information for the public hearing associated with this rulemaking

Proposed rule amendments:

Summary of triennial review proposed amendments:

  • Triennial review summary presentation (EMC approved March 11, 2021)
  • Cadmium
  • Cyanide
    • Update the current Class C aquatic life standard for Cyanide to include the option to analyze Cyanide as either free or total Cyanide. This will align the current Class C standard for total Cyanide with the EPA National Recommended Water Quality Criteria which recommends analysis as free Cyanide. 
    • References:
  • Definitions
    • Add new definitions for the terms "Lentic" and "Lotic" (associated with the proposed selenium standard)
    • Provide clarification for the existing "Industrial discharge" definition
  • Eastern Band of Cherokee Indians
    • Amend language in 15A NCAC 02B .0301 to address unnamed tributaries entering Eastern Band of Cherokee Indian boundaries
  • Recreational criteria (E. coli)
    • Establish a site-specific E. coli Primary Recreation (Class B) surface water standard for the 19 counties that comprise the Asheville region of North Carolina. E. coli would replace fecal coliform as the pathogenic indicator in these Class B waters.
    • References:
  • Selenium
  • 1,4-Dioxane
  • Technical corrections
    • Include technical corrections to existing language in the following rules:
      • 15A NCAC 02B .0215 
      • 15A NCAC 02B .0216
      • 15A NCAC 02B .0311

More Information:

For additional information and questions please contact: Christopher Ventaloro, Water Quality Standards Coordinator, at

2017-2019 Triennial Review

2007-2015 Triennial Reviews

2004-2006 Triennial Review

2000-2003 Triennial Review



Associated Files