Statewide Aquatic Toxicity Provisions

The Toxicity Provisions (Provisions) include statewide numeric water quality objectives for both acute and chronic toxicity and a program of implementation to control toxicity. The Provisions provide consistent protection of aquatic life beneficial uses in inland surface waters, enclosed bays, estuaries, and coastal lagoons throughout the state from the effects of known and unknown toxicants. The Provisions were adopted by the State Water Resources Control Board (State Water Board) on December 1, 2020. On October 5, 2021, the State Water Board adopted a resolution to confirm that the Provisions were adopted as state policy for water quality control for all inland surface waters, enclosed bays, estuaries, and coastal lagoons of the state. The Provisions were approved by the California Office of Administrative Law pursuant to Government Code section 11353 on April 25, 2022. The Provisions were approved by the U.S. Environmental Protection Agency, consistent with the requirements of section 303(c) of the Clean Water Act and 40 C.F.R. Part 131, on May 1, 2023.

• November 19, 2024 - Toxicity Provisions Implementation Status Report (PDF)
• November 17, 2021 - Toxicity Provisions Fact Sheet (PDF)
• April 2, 2021 - TST Spreadsheet Tool - Version 1.9
  • This spreadsheet tool is being provided to assist interested stakeholders in evaluating their data using the TST. The user should note that this spreadsheet tool is subject to change without notice and should not be used for official data interpretation.

For additional information, or to request the documents below, please contact Zane Poulson at Zane.Poulson@waterboards.ca.gov

Final Documents

• January 20, 2022 – State Policy for Water Quality Control: Toxicity Provisions adopted on December 1, 2020, and revised on October 5, 2021 (PDF)
• January 20, 2022 – Staff Report, Including Substitute Environmental Documentation for State Policy for Water Quality Control: Toxicity Provisions adopted on December 1, 2020, and revised on October 5, 2021 (PDF)
• December 1, 2020 – Resolution No. 2020-0044 (PDF)
• October 5, 2021 – Resolution No. 2021-0044 (PDF)
• January 20, 2022 – Memo: Minor, Non-Substantive Changes to the Toxicity Provisions (PDF)
• Comments & Response to Comments
  • September 30, 2021 – Revised Response to Comments on the Proposed Resolution (PDF)
  • June 3, 2021 – Final Summary of Comments and Responses on Appendices J and K and the Differences Between the October 2018 and July 2020 Versions of the Toxicity Provisions and Staff Report (DOCX)
  • July 22, 2020 - Summary of Comments and Responses on the 2018 Draft Toxicity Provisions and 2018 Draft Staff Report (DOCX)
  • October 26, 2018 – Response to Comments on the 2012 Draft Policy for Toxicity Assessment and Control (PDF)
• July 20, 2020 - Economic Considerations of Proposed Whole Effluent Toxicity Control Provisions for California (PDF)

Office of Administrative Law (OAL) Approval

• April 25, 2022 – Notice of Approval of Regulatory Action (PDF) – Available upon request
• April 25, 2022 – Endorsed and approved Form 400 (PDF) – Available upon request

U.S. Environmental Protection Agency (EPA) Approval

• May 1, 2023 – Approval of New Water Quality Standards: California State Policy for Water Quality Control: Toxicity Provisions (PDF) – Available upon request

State Water Board Meetings

• October 5, 2021 Board Meeting, Agenda Item #7 - Consideration of a proposed Resolution rescinding the December 1, 2020, establishment of Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California and confirming that the “Toxicity Provisions” were adopted as State Policy for Water Quality Control for all waters of the State.
• December 1, 2020 Board Meeting, Agenda Item #5 - Consideration of a proposed Resolution establishing the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions.
• November 28, 2018 Board Meeting, Agenda Item #6 - The State Water Board will hold a Public Hearing on the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions

Ceriodaphnia dubia Study

• January 2, 2024 – Ceriodaphnia dubia Resources Document (PDF).
• September 30, 2023 – Ceriodaphnia dubia Quality Assurance Guidance Recommendations Technical Report (PDF).
• October 17, 2023 Board Meeting, Agenda Item #4 – Report on quality assurance recommendations for the Ceriodaphnia dubia Toxicity Test and an update on the status of implementation of the Toxicity Provisions.
• May 4, 2021 Board Meeting, Agenda Item #4 – Update on the study for the development of quality assurance recommendations for laboratories conducting the Ceriodaphnia Dubia toxicity test.

For more information, please visit the "Ceriodaphnia Toxicity Testing Quality Assurance" webpage on the Southern California Coastal Water Research Project Authority (SCCWRP) website: https://www.sccwrp.org/about/research-areas/additional-research-areas/ceriodaphnia-toxicity-testing-quality-assurance/

Alternative Test Procedure (ATP)

• December 20, 2023 – Request from the Water Boards to U.S. EPA for review and approval of a one effluent concentration ATP for whole effluent toxicity testing (PDF)
• December 14, 2023 – Application for One Effluent Concentration Alternative Test Procedure for Whole Effluent Toxicity Testing (PDF)
  • Attachment 1. Current Non-Storm Water NPDES Permits as of October 1, 2023 (PDF)
  • Attachment 2. Current Storm Water and General NPDES Permits as of October 1, 2023 (PDF)
  • Attachment 3. Laboratories with ELAP Accreditation in WET Methods as of December 1, 2023 (PDF)
  • Attachment 4. Summary of Aquatic Toxicity Test Costs (PDF)

Other Related Projects

• Water Quality Control Plan for Ocean Waters of California (webpage coming soon)

Staff Contact Information

Zane Poulson, Project Manager
Email: Zane.Poulson@waterboards.ca.gov

Katie Fong, Staff
Email: Katie.Fong@waterboards.ca.gov

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