Subject of Possible Rule Making: The Washington state department of ecology (ecology) is considering revisions to chapter 173-201A WAC, Water quality standards for surface waters of the state of Washington, to add criteria that will protect aquatic life, recreation, and drinking water sources in lakes and reservoirs from nutrient pollution.

Statutes Authorizing the Agency to Adopt Rules on this Subject: RCW 90.48.035 Water pollution control—Rule-making authority; and 40 C.F.R. 131.20 Water Quality Standards - State review and revision of water quality standards, requires states and tribes (with primacy for clean water actions) to periodically review and update the water quality standards.

Reasons Why Rules on this Subject may be Needed and What They Might Accomplish: Excess nutrients can contribute to harmful algal blooms, which can lower oxygen levels in the water, negatively impact recreation, and overall reduce the health of people and the environment.

We will review the United States Environmental Protection Agency's (EPA) final recommended criteria for total nitrogen, total phosphorus, and chlorophyll a, in addition to any other up-to-date information, to develop protective criteria for Washington's lakes and reservoirs.

During the 2025 triennial review of the surface water quality standards, we committed to prioritizing this rule making in the next three years. We are now ready to begin that effort.

Other Federal and State Agencies that Regulate this Subject and the Process Coordinating the Rule with These Agencies: Coordinating federal and state agencies include the EPA, National Oceanic and Atmospheric Administration, United States Fish and Wildlife Service, and the Washington state department of health.

Process for Developing New Rule: Ecology will follow the standard process for the adoption of rules under the Administrative Procedure Act (chapter 34.05 RCW).

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 47696, Olympia, WA 98504-7696, phone 360-789-3610, Washington relay service or TTY call 711 or 877-833-6341, email marla.koberstein@ecy.wa.gov, website https://ecology.wa.gov/regulations-permits/laws-rules-rulemaking/rulemaking/wac-173-201A-lake-nutrient-criteria. Sign up to receive email notices at https://public.govdelivery.com/accounts/WAECY/subscriber/new?topic_id=WAECY_61.

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

Ecology will conduct an environmental justice assessment in accordance with RCW 70A.02.060 as a part of this rule making.