Updates to the surface water quality standards

We update the surface water quality standards to incorporate the latest science and to meet our priorities and commitments regarding the standards.

Current actions 

The following information highlights the most recent actions related to the water quality standards in Washington.

Human health criteria

On March 28, 2022, the Environmental Protection Agency (EPA) proposed a rule for the human health criteria for the state of Washington’s waters, returning the standards to what EPA had originally approved in 2016 after they had changed in 2020. Currently, EPA is conducting a 60-day public comment period for the proposed rule.

Until a new federal rule is finalized the criteria that are in place are listed in WAC 173-201A-240, Toxic Substances Criteria, with the exception for the following chemicals: arsenic, methylmercury, and bis (2-chloro-1-methylethyl) ether, which continue to have federal criteria

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. 

 Recent and current rulemaking

We use the rulemaking process to meet our priorities and commitments regarding the standards.

Recently completed rulemaking

Triennial review 

Federal regulations require that we periodically hold public hearings to review surface water quality standards. This process is called a triennial review. This review gives us an opportunity to discuss priorities and commitments to update surface water quality standards with interested parties and the public. 

2021 triennial review

In April 2022, we submitted our Triennial Review Report to EPA with our planned updates to Washington's Surface Water Quality Standards anticipated for 2022 through 2024.

This latest Triennial Review resulted from a public review process that we conducted from July to September 2021. We accepted comments and feedback on a draft work plan of actions we expect to take related to our water quality standards in the next three years. 

We've used rulemaking to continually update the water quality standards. See our recent rulemaking section above to learn more about these updates. 

Rulemaking process

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.

Topics are prioritized based on:

  • The expected environmental benefits.
  • Changes in science
  • Federal mandates or legal requirements.
  • Requests for specific updates.