Chapter 173-201A WAC (Chelan UAA)

We are beginning a rulemaking to consider amending chapter 173-201A WAC - Water Quality Standards for Surface Waters of the State of Washington.

We are considering the following changes:

  • Amending WAC 173-201A-440 (Use attainability analysis)
  • Changing the designated use for the Chelan River in WAC 173-201A-602 and potentially creating a new section in WAC 173-201A-630 and WAC 173-201A-632

Other sections of Chapter 173-201A WAC may be amended, as necessary, to support any revisions to the sections noted above.

We are considering a change to the aquatic life designated use of salmonid spawning, rearing, and migration on the Chelan River using a use attainability analysis (UAA). A UAA is an approved water quality tool in Washington’s surface water quality standards (WAC 173-201A-440) and is used for removing a designated use for a water body only if that use is not existing or attainable. A UAA is a scientific assessment of the physical, chemical, biological, and economic factors that may affect the attainment of the use.

We are also considering including corresponding temperature and dissolved oxygen criteria, to align with the highest achievable water quality.

Rulemaking timeline


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