Water

Water Quality Standards

Water Quality Standards:

  • Protect water resources for uses such as fishing, swimming and other recreation, and sustaining fish, bugs, plants, and other aquatic life
  • Are a measure to identify polluted waters or healthy waters in need of protection
  • Guide the limits set on what regulated facilities can discharge to surface water

The federal Clean Water Act requires states to designate beneficial uses for all waters and develop water quality standards to protect each use. Water quality standards consist of several parts:

  • Beneficial uses — Identify how people, aquatic communities, and wildlife use our waters
  • Numeric standards — Amounts of specific pollutants allowed in a body of water and still protects it for the beneficial uses
  • Narrative standards — Statements of unacceptable conditions in and on the water
  • Nondegradation protections — Extra protection for high-quality or unique waters and existing uses

Together, the beneficial uses, numeric and narrative standards, and nondegradation protections provide the framework for achieving Clean Water Act goals and protecting Montana water resources.