Copper TMDLs

December 2, 2022- Regional Board Hearing

On December 2, 2022, the Santa Ana Regional Water Quality Control Board adopted Resolution No. R8-2022-0012 to incorporate Copper Total Maximum Daily Loads (TMDLs) for Newport Bay, Orange County, California into the Water Quality Control Plan for the Santa Ana River Basin (the Basin Plan Amendment).

• Basin Plan Amendment (BPA) Cu TMDLs - Attachment A to Resolution 2022-0012
• Basin Plan Amendment (BPA) Cu TMDLs - Attachment B to Resolution 2022-0012
• Substitute Environmental Document (SED) - Cu TMDLs
• Staff Report - Cu TMDLs - SED Appendix A
• SED Appendix B-1a Responses to 2016 Comments Document (2018)
• SED Appendix B-1b Responses to 2016 Board Meeting Comments Document (2021)
• SED Appendix B-2 Responses to August 2018 Comments Document (2021)
• SED Appendix B-3 Responses to 2019 Workshops Comments Document (2021)
• SED Appendix B-4 Responses to August 2021 Comments - Cu TMDLs (2022)
• SED Appendix B-5 Responses to County-City Alternative Implementation Proposal
• Notice of Public Hearing & Filing (October 18, 2022)

August 5, 2025- State Water Board Hearing

The State Water Resources Control Board approved the Basin Plan Amendment under Resolution No. 2025-0023 on August 5, 2025

• Final Responses to Cu TMDL Comments

April 28, 2026 – OAL Approval

On April 28, 2026, the Office of Administrative Law approved the Regulatory Provisions for the Newport Bay Copper TMDLs (OAL Matter Number: 2026-0318-05S) pursuant to section 11353 of the Government Code. The Regulatory Provisions were endorsed and filed in the office of the Secretary of State of the State of California on April 28, 2026.

• Concise Summary of Regulatory Provisions

Next Steps

The Basin Plan Amendment incorporating the Copper TMDLs for Newport Bay will be submitted to the United States Environmental Protection Agency for review and approval. Portions of the Basin Plan Amendment not requiring USEPA approval are in effect for purposes of state law.

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Please direct questions to Lauren Hubbell at lauren.hubbell@waterboards.ca.gov or (951) 320-6375.

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