Statewide Toxicity Provisions

On December 1, 2020, the State Water Resources Control Board (State Water Board) adopted statewide numeric water quality objectives for both acute and chronic toxicity and a program of implementation to control toxicity, which are collectively known as the Toxicity Provisions. The Provisions provide consistent protection of aquatic life beneficial uses in inland surface waters, enclosed bays, and estuaries throughout the state, and protect aquatic habitats and life from the effects of known and unknown toxicants. The Provisions are not yet in effect. The Provisions will take effect upon approval by the California Office of Administrative Law for purposes of state law and upon approval by the U.S. Environmental Protection Agency for purposes of federal law.

Current Announcements

On October 5, 2021, the State Water Board will receive public comments regarding a proposed resolution to confirm that the Toxicity Provisions were adopted as state policy for water quality control for all inland surface waters, enclosed bays, estuaries, and coastal lagoons of the state and rescind the State Water Board’s action to establish the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California.

September 30, 2021 – Revised Response to Comments on the Proposed Resolution (PDF)
September 24, 2021 – Revised Proposed Resolution (Word Document)
September 24, 2021 – Agenda (PDF) for the State Water Board meeting to be held on October 5, 2021
September 21, 2021 – Response to Comments on the Proposed Resolution (PDF)
June 25, 2021 – Notice of Opportunity for Public Comment and Notice of Public Hearing and Consideration (PDF)
June 25, 2021 – Proposed Resolution (Word Document)
June 28, 2021 – Resolution No. 2020-0044, adopted on December 1, 2020 (PDF)

June 3, 2021 – Toxicity Provisions adopted on December 1, 2020 (PDF)
June 3, 2021 – Final Staff Report, Including Substitute Environmental Documentation adopted on December 1, 2020 (PDF) – Includes changes to conform with the Toxicity Provisions adopted on December 1, 2020, which allowed additional routine monitoring tests to be initiated up to two weeks after the calendar month in which the MMEL or MDEL violation occurred and which clarified the definition of the instream waste concentration. These conforming changes to the Staff Report are identified in editor’s notes in the footnotes on pages viii, 25, 136, 138, and 147.
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 (Word Document)

Ceriodaphnia dubia Study

Updated September 27, 2021 – Stakeholder Advisory Committee Member Names, Affiliations, and Email Addresses (PDF)
December 8, 2020 – Agenda for first Stakeholder Advisory Committee Meeting, scheduled for December 8, 2020 (PDF)
October 30, 2020 – Development of Quality Assurance Recommendations for the Ceriodaphnia dubia Toxicity Test – Excerpt from contract between the State Water Resources Control Board and the Southern California Coastal Water Research Project Authority (Agreement Number 19-078-270) (PDF)

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)

November 25, 2020 – ATP Request Letter (PDF)

2020 Revised Draft Toxicity Provisions Documents

November 9, 2020 – 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 (Word Document)
October 30, 2020 – Proposed Final Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries; and Toxicity Provisions

October 30, 2020 – Proposed Final Staff Report, Including Substitute Environmental Documentation for the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions

October 12, 2020 – Notice of Public Meeting, Consideration of Adoption, and Document Availability (PDF)
July 27, 2020 - Summary of Significant Changes Made Between the October 2018 Draft Toxicity Provisions and the July 2020 Draft Toxicity Provisions (PDF)
July 22, 2020 - Summary of Comments and Responses on the 2018 Draft Toxicity Provisions and 2018 Draft Staff Report (Word Document)
July 7, 2020 - Second Revised Draft Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries; and Toxicity Provisions (Word Document)
July 7, 2020 - Second Revised Draft Staff Report, Including Substitute Environmental Documentation for the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions (Word Document)
July 7, 2020 - Revised Notice (Word Document) | Notice of Public Staff Workshop, Public Comment Period, 2018 Response to Comments, and Proposed Second Revised Toxicity Provisions and Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (PDF)
July 20, 2020 - Economic Considerations of Proposed Whole Effluent Toxicity Control Provisions for California (PDF Document)

2020 Staff Workshop Presentations

July 29, 2020 - Staff Public Workshop Presentation (PDF)
January 9, 2020 - Staff Public Workshop Presentation (PDF)

2019 Revised Draft Toxicity Provisions Documents

January 10, 2020 – First Revised Staff Report Appendix J. Evaluating Laboratory Performance with the Chronic Ceriodaphnia dubia Reproduction Toxicity Test (PDF)
January 6, 2020 – Staff Report Appendix J Reference: Fox 2019 Memorandum: Probability of Failing TST and WET Maximum Monthly Effluent Limit (PDF)
January 6, 2020 – Staff Report Appendix J Reference: Data used in Staff Analysis portion of Appendix J (Microsoft Excel format)
January 6, 2020 – Staff Report Appendix J Reference: EPA’s Test of Significant Toxicity: Impact on the Permit Compliance of Honolulu’s Wastewater Treatment Plants (PDF)
December 24, 2019 – Staff Report Appendix J. Evaluating Laboratory Performance with the Chronic Ceriodaphnia dubia Reproduction Toxicity Test (PDF)
December 24, 2019 – Staff Report Appendix K. Survey of Laboratory Toxicity Testing Logistical Capacities (PDF)
December 24, 2019 – Notice of Availability of Staff Report Appendices and Opportunity for Public Comment and Public Staff Workshop and Proposed First Revised Toxicity Provisions and Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (PDF)
July 25, 2019 – First Revised Draft Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries; and Toxicity Provisions (PDF)
July 25, 2019 – First Revised Draft Staff Report, Including Substitute Environmental Documentation for the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions (PDF)
December 5, 2019 – Fox et al. 2019 publication is available at: https://setac.onlinelibrary.wiley.com/doi/pdf/10.1002/etc.4347
October 25, 2019 – Notice of Public Staff Workshop and Proposed First Revised Toxicity Provisions and Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (PDF)
September 30, 2019 – Aquatic Toxicity Provisions: Improving Protection for California’s Rivers, Lakes, Enclosed Bays and Estuaries (Fact Sheet) (PDF)
August 6, 2019 – Revised Notice of Public Staff Workshops and Public Board Workshop and Proposed First Revised Toxicity Provisions and Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (PDF)

2019 Staff Workshop Presentations

November 15, 2019 – Fourth Public Staff Workshop Presentation (PDF)
October 3, 2019 - Board Workshop Presentation (PDF)
August 28, 2019 – Third Staff Public Workshop Presentation (PDF)
August 16, 2019 – Second Staff Public Workshop Presentation (PDF)
August 13, 2019 – First Staff Public Workshop Presentation (PDF)

2018 Draft Toxicity Provisions Documents

2018 Draft Toxicity Provisions and Staff Report Comment Letters
October 19, 2018 – Draft Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries; and Toxicity Provisions (PDF)
October 19, 2018 – Draft Staff Report, Including Substitute Environmental Documentation for the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions (PDF)
- Revised Appendix G. Flow Chart (PDF). Appendix G contains a flow chart that illustrates the proposed Toxicity Reduction Evaluation Process. The Draft Staff Report that was released on October 19, 2018 contained an incorrect version of this flow chart. This PDF is the correct version.
November 11, 2018 – Agenda for the State Water Board Hearing on Wednesday, November 28, 2018 (PDF; see Item 6).
October 31, 2018 – Toxicity Workshop Presentation (PDF).
October 1, 2018 – Notice of Opportunity for Public Comment, Public Staff Workshops, Public Board Hearing, and Notice of Filing for the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions (PDF)
- A Revised Notice of Opportunity for Public Comment, Public Staff Workshops, Public Board Hearing, and Notice of Filing for the Proposed Establishment of the Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California; and Toxicity Provisions (PDF) is now available.
October 26, 2018 – Response to Comments on the 2012 Draft Policy for Toxicity Assessment and Control (PDF)
please contact program for appendices and attachments
- 2012 Comment Letters with Numbered Comments
April 2017 Outreach Document (Posted 10/03/17) (PDF)
April 2017 Outreach Presentation (Posted 10/03/17) (PDF)

2012 Draft Toxicity Policy

In 2012, the State Water Board released a draft Policy for Toxicity Assessment and Control for public comment.

Draft Policy for Toxicity Assessment and Control - Public Review Draft, June 2012
Draft Staff Report for Toxicity Assessment and Control - Public Review Draft, June 2012
Notice of Opportunity for Public Comment, Public Hearing, and Filing for the Policy for Toxicity Assessment and Control - Public Review Draft, June 2012 (posted 06/27/12)
Comments Received

Staff Presentation (posted 10/01/12)
Policy for Toxicity Assessment and Control Brochure (posted 10/01/12)

Policy for Toxicity Assessment and Control - Public Review Draft, June 2012
Staff Report for Toxicity Assessment and Control - Public Review Draft, June 2012

External Peer Review

The following journal articles are referenced in the TST peer review synopsis.

Test of Significant Toxicity (TST)

Toxicity Assessment and Control in California’s Surface Waters (Fact Sheet) - issued August 2011
TST Spreadsheet Tool - Version 1.9 (updated 4/02/2021) 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.

TST Test Drive

Raw Data from the Final Whole Effluent Toxicity Test Drive Analysis of the TST is now available. In response to stakeholder requests, the State Water Board is publishing the raw data used for the 2011 TST Test Drive Analysis. These datasets aggregate the replicate and test endpoint values for each individual test, as well as the intermediate and final calculations for the statistics used in the analysis.

The Appendix A files are data from tests of effluent from individual dischargers, as summarized in Appendix A in the Test Drive Analysis. The data are separated into individual files that compile the data for specific type of tests. The Appendix B file is the entire dataset of ambient data used in Appendix B of the Test Drive Analysis.
- Appendix A
- Appendix B
  - All Ambient Toxicity Test Data
Appendix A and Appendix B data from the Final Whole Effluent Toxicity Test Drive Analysis of the TST in Microsoft Excel format
Final Whole Effluent Toxicity Test Drive Analysis of the TST - updated December 2011

2010 Draft Policy for Toxicity Assessment and Control and 2011 Workshops

2006 Public Scoping Meeting

Get updates by email regarding the draft Policy for Toxicity Assessment and Control, subscribe online to the “Freshwater Plans and Policies” mailing list.