Subject of Possible Rule Making: The department of ecology (ecology) is beginning a rule making to consider amending the water quality standards for surface waters of the state of Washington, chapter 173-201A WAC.

The proposed amendments include: Amending WAC 173-201A-440 Use attainability analysis; and changing the designated use for the Chelan River in WAC 173-201A-602 and potentially create new WAC 173-201A-630 and 173-201A-632.

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 (SWQS), 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.

Reasons Why Rules on this Subject may be Needed and What They Might Accomplish: On December 20, 2019, Public Utility District No. 1 of Chelan County (Chelan PUD) submitted a proposal for a UAA for the aquatic life designated use on the Chelan River to better reflect current and historical uses. The current use designation includes salmonid spawning, rearing and migration for the entire river.

The Lake Chelan hydroelectric project was relicensed by the Federal Energy Regulatory Commission (FERC) in 2006. As part of the relicensing, ecology issued a 401 Water Quality Certification (401 Certification). The FERC license required Chelan PUD to rewater the river from which flows had been diverted for hydropower for over eighty years.

The returned waters now flow year-round through the four miles of the Chelan River to the confluence with the Columbia River. The Chelan River travels through a naturally steep canyon that acts as a barrier to salmonid migration to most of the river. However, salmonids now return to spawn in the lowest half-mile reach near the confluence with the Columbia.

In response to new license conditions, the Chelan PUD implemented a series of fishery studies as well as habitat and flow improvement projects to meet salmonid spawning, survival, and habitat use objectives in the lower reach of the river, and to assess the potential for resident fish habitat in the upper reaches. After ten years of monitoring, adaptive management, and consultation with the Chelan River Fishery Forum, Chelan PUD reported on what biological objectives were met and why some other objectives were not met. The final report proposed changes to the Chelan River aquatic life designated uses, including corresponding temperature and dissolved oxygen criteria, to align with the highest achievable water quality.

Ecology's 401 Certification of Chelan's FERC license provides that ecology make a determination, based on the outcome of the evaluation of the monitoring and adaptive management program, to modify the water quality standards to reflect the objectives achieved.

Based on the previous research and consultation with ecology and the Environmental Protection Agency (EPA), Chelan PUD submitted a UAA proposal. We responded to the UAA request on February 18, 2020, and confirmed that the information provided is sufficient to proceed toward rule making in accordance with WAC 173-201A-440. We will consider using the UAA submittal to assign more accurate aquatic life designated uses to the Chelan River.

In addition to Washington state rules, the process to amend the uses must be consistent with federal EPA regulations on designating and protecting uses under 40 C.F.R. 131.10. The results of a UAA will not be in effect until they have been incorporated into the water quality standards (chapter 173-201A WAC) and approved by EPA.

Other Federal and State Agencies that Regulate this Subject and the Process Coordinating the Rule with These Agencies: We will work with the federal EPA to ensure that the adopted water quality standards meet Clean Water Act requirements. We will consult with tribes during all stages of rule development. We will work with the Chelan River Fisheries Forum, which includes the National Oceanic and Atmospheric Administration, National Parks Service, United States Fish and Wildlife Service, Washington department of fish and wildlife, the United States Forest Service, the Confederated Tribes and Bands of the Yakima Nation, the Confederated Tribes of the Colville Reservation, and the Confederated Tribes of the Umatilla Indian Reservation. We will also work with city and county governments, public utility districts, and entities noted above, to discuss and seek input on rulemaking language development.

Interested parties can participate in the decision to adopt the new rule and formulation of the proposed rule before publication by contacting Marla Koberstein, Department of Ecology, Water Quality Program, P.O. Box 47600, Olympia, WA 98504-7600, phone 36[360]-407-6413, people with speech disability may call TTY at 877-833-6341. People with impaired hearing may call Washington relay service at 711, email swqs@ecy.wa.gov, website www.ecology.wa.gov/Regulations-Permits/Laws-rules-rulemaking/Rulemaking/WAC173-201A-Chelan-UAA, sign up to receive email notices at http://listserv.ecology.wa.gov/scripts/wa-ECOLOGY.exe?SUBED1=ECOLOGY-WATER-QUALITY-INFO&A=1.

Additional comments: Interested parties can stay informed about the rule making and public involvement opportunities as described above. Ecology will extend an offer for government-to-government consultation with tribal governments during each phase of rule development.