Comment on the performance-based approach methods document
We are accepting comments on the revised draft of a methods document that provides the information and process we must follow to calculate natural conditions site-specific criteria. This document is called A Performance-Based Approach for Developing Site-Specific Natural Conditions Criteria for Aquatic Life in Washington. This document is not rule language, but it supports the recent rulemaking on natural conditions. This methods document will cover marine dissolved oxygen natural conditions first. We anticipate future chapters to address other conventional pollutants. A formal announcement was published in the Washington State Register on April 2, 2025.
We are accepting comments from 12 a.m. on March 25 until 11:59 p.m. on May 22, 2025
After registering, you will receive a confirmation email containing information about joining the meeting, including joining by phone only.
The hearing will begin with a brief presentation on the draft performance-based approach document and time for questions, followed by an opportunity to provide formal comments. The hearing will end once everyone who wants to provide comments has the opportunity to do so. Written comments will receive the same consideration as verbal testimony.
Next steps
After the close of comment period, we will publish our response to comments received and the final performance-based approach document. Then, the Office of the Attorney General will certify that the document is legally binding, and we will send the performance-based approach document to the EPA for review and action. We will also send the rule language we adopted in Nov. 2024, related to natural conditions provisions and the performance-based approach, to EPA for review at the same time.
Current rulemaking
We use the rulemaking process to meet our priorities and commitments regarding the standards.
We do not have any current rulemakings open. We will be using the 2025 Triennial Review process to plan the next set of updates to the standards.
We adopted revisions to address the Environmental Protection Agency’s 2021 disapproval of Washington's natural condition provisions in our standards, including for fresh and marine dissolved oxygen and temperature (excluding lakes).
These rule amendments have not yet been approved by EPA for use in Clean Water Act programs.
While we added a new section in the rule to define a method called a “performance-based approach” to determine natural conditions criteria values, the methods Ecology will use to determine the criteria will be in a separate document. We are accepting comments on this revised draft. We will carefully consider comments received and publish a final version of the publication alongside our response to comments by Summer 2025. After we finalize the Performance-Based Approach document next year, we will send the document to EPA for review and approval.
On Nov. 19, 2021, EPA notified Ecology of a disapproval on our previously approved natural condition provisions in our Surface Water Quality Standards. The natural conditions provisions recognize that some water bodies have poorer water quality due to natural (not human caused) conditions like climate or landscape. Although these provisions have been a part of state water quality standards since 1967, EPA agreed to reconsider whether this part of our standards are currently sufficient. As a result, EPA disapproved the following sections of our surface water quality standards:
A general provision that allows a water body’s natural conditions to serve as the water quality standard. [WAC 173-201A-260(1)(a)]
A specific provision that sets the temperature requirement of how cool a water body would be without human alterations. This provision also limits temperature increases caused by human activity to less than 0.3 degrees Celsius. [WAC 173-201A-200(1)(c)(i); -210(1)(c)(i))]
A specific provision that sets the dissolved oxygen requirement to be at the highest levels a water body can achieve without human alterations. This provision also states that human activity cannot cumulatively cause dissolved oxygen in a water body to decrease more than 0.2 mg/L. [WAC 173-201A-200(1)(d)(i); -210(1)(d)(i)]
The numeric water quality criteria for temperature, dissolved oxygen, and all other parameters still remain in place. This disapproval only removes our ability to include the natural variations of water conditions in some of our water quality decisions.
We are considering revisions to address EPA's 2021 disapproval of Washington's natural condition provisions in our standards, including for fresh and marine dissolved oxygen and temperature (excluding lakes).
In addition, on Sept. 30, 2021, EPA notified Ecology of a disapproval on our previously approved water quality standards provision that allows short-term modifications of the standards for some qualifying activities in WAC 173-201A-410. In 2006, we added additional options to allow the standards to be modified during major watershed restoration activities that may take a longer amount of time than previously defined as short-term, this is no longer allowed using the short-term modification provision.
In this action, EPA also disapproved water quality temperature limits on discharges that create a thermal plume in the receiving water body [WAC 173-201A-200(1)(c)(vii)(C); -200(1)(c)(v)(C)]. Although this limit is used for some discharges, protective numeric temperature limits still apply.
We adopted revisions to the aquatic life toxics criteria to provide additional water quality protection for organisms that live in water. We reviewed all of Washington’s current aquatic life toxics criteria to ensure they are consistent with nationally recommended water quality criteria issued by the Environmental Protection Agency.
These rule amendments have not yet been approved by EPA for use in Clean Water Act programs.
Read our blog and news release to learn more about aquatic life toxics criteria.
We adopted changes to Washington's surface water quality standards. These changes better protect water quality and physical habitat for incubating eggs and young salmon in rivers and streams. The changes will further ensure salmon nests, called redds, have enough oxygen to support early life stages of salmon. We also added better protection to these early life stages of salmon from the harmful effects of too much fine sediment that can clog important spawning gravels where redds are located.
These rule amendments have not yet been approved by EPA for use in Clean Water Act programs.
Read our blog to find out more about how this rulemaking better protects salmon.
We made changes to the aquatic life designated use of salmonid spawning, rearing, and migration on the Chelan River through a use attainability analysis (UAA) and rulemaking process. These adopted changes to the designated uses and criteria for the Chelan River were in response to a rulemaking request from the Public Utility District No. 1 of Chelan County (Chelan PUD).
Chelan PUD returned year-round flows to the Chelan River and established habitat along the river, and conducted a 10-year monitoring and adaptive management program to meet spawning, survival, and habitat use objectives for Chinook salmon, steelhead, and resident fish. Following this work, Chelan PUD submitted a request for a Use Attainability Analysis rulemaking for the aquatic life designated use on the Chelan River to better reflect current and historical uses.
A UAA is an approved water quality tool in Washington’s surface water quality standards (WAC 173-201A-440) and is used for removing or revising 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.
These rule amendments have not yet been approved by EPA for use in Clean Water Act programs.
Ecology adopted amendments to the human health criteria and associated footnotes in Table 240 of WAC 173-201A-240, to incorporate existing federal human health criteria for Washington into the state water quality standards.
Read our news release to find out more about this rule update.
This rulemaking returns the human health criteria to what EPA had originally approved in 2016, before they changed in 2020. EPA took comments on a draft rule from March 28, 2022 until May 31, 2022.
Timeline of EPA actions:
Nov. 15, 2016 – EPA partially approved and partially disapproved certain human health criteria that Ecology submitted to EPA on Aug. 1, 2016.
May 10, 2019 – EPA released a statement that they are reversing their 2016 decision and approving the human health criteria standards Washington submitted in 2016.
July 23, 2019 – EPA announced a draft rule to withdraw the federal water quality standards for certain human health criteria in Washington (40 CFR 131.45).
April 16, 2020 – EPA announced their final rule to withdraw the federal water quality standards for certain human health criteria in Washington (40 CFR 131.45), no effective date stated.
May 13, 2020 – EPA published the final rule in the Federal Register to withdraw the federal water quality standards for certain human health criteria in Washington (40 CFR 131.45). The final rule went into effect on June 12, 2020.
June 30, 2021 – EPA files a motion with federal court to provide time to propose new human health criteria for Washington.
March 28, 2022 – EPA proposed a rule to promulgate human health criteria for the state of Washington’s waters that EPA had originally promulgated in 2016 but later removed in 2020.
The following are responses to EPA's actions from Ecology and other state agencies along with our press releases and formal comments on the rulemaking.
We adopted outstanding resource water designations for the following water bodies under WAC 173-201A-330 (Antidegradation Tier III – Protection of Outstanding Resource Waters):
Soap Lake (Grant County)
Napeequa River (Chelan County)
Green River (Lewis and Skamania counties)
Cascade River (Skagit County)
Read our blog to learn more about outstanding resource water designations.
This rulemaking adopted multiple revisions including changes to the numeric criteria for total dissolved gas in the Snake and Columbia rivers. We adopted changes to the total dissolved gas criteria to allow more water to spill over dams to help salmon migrate. Read our blog to learn about the environmental impacts of allowing more water over the dams.
Triennial Review
Federal regulations require that we hold public hearings to review surface water quality standards. This process occurs every three years and is called a triennial review. This review gives us an opportunity to discuss priorities and commitments to update surface water quality standards with Tribes, interested parties, and the public.
2025 triennial review
We have started the triennial review of the surface water quality standards. As part of this process, we have evaluated the need to update the standards to align with federally recommended criteria, to address new scientific information, and to reflect state priorities. We have provided a list of priority actions for the next three years for feedback. You can also give us feedback on any part of the surface water quality standards in Chapter 173-201A WAC, even if it’s not a project listed in the workplan.
The hearing will begin with a brief presentation on the workplan, followed by an opportunity to provide formal comments. The hearing will end once everyone who wants to provide comments has the opportunity to do so. Written comments will receive the same consideration as verbal testimony.
The Triennial Review is a public involvement opportunity that helps inform and prioritize revisions to the surface water quality standards for the next three years. This is not a rulemaking process; rather, it is a planning process to help guide actions necessary to keep the standards current.
During the Triennial Review, we:
Review the water quality standards to identify needed updates based on the Environmental Protection Agency recommendations, new scientific information, and agency priorities
Draft a workplan that outlines our priority actions for the next three years
Get feedback on the plan and make revisions based on comments we receive
Send the final plan to the EPA
Begin rulemakings and other actions as listed in our workplan
Each rulemaking project identified as a priority will have its own public process to formally comment on proposed rule changes, in accordance with Washington’s Administrative Procedure Act (APA) at Chapter 34.05 Revised Code of Washington (RCW) and the Code of Federal Regulations (CFR) at 40 CFR part 25. Priorities identified in a triennial review will be incorporate as commitments in Ecology's Performance Partnership Agreement with EPA.
When it is necessary to update the standards we go through the rulemaking process. We select the topics for rulemaking based on which actions will make the greatest environmental and/or administrative benefits.
