Title
Update on Copper TMDLS in Newport Harbor
Recommendation
In 2022, the Santa Ana Regional Water Quality Control Board adopted a Total Maximum Daily Load (TMDL) for copper in Newport Bay to meet the U.S. Environmental Protection Agency’s California Toxics Rule standard of 3.1 parts per billion (ppb) for dissolved copper. Approved by the State Water Resources Control Board in 2025, the TMDL establishes a 12-year schedule to achieve a 60% reduction in copper loading, primarily targeting leaching from copper-based antifouling paints on vessel hulls.
The City of Newport Beach has taken a proactive role in implementing TMDL requirements through water quality monitoring, public education, best management practices, and collaboration with the California Department of Pesticide Regulation and regional partners. Monitoring results indicate that copper concentrations are trending downward and, in many areas, already meet water quality objectives.
Although challenges remain-such as technical uncertainties, limited alternatives to copper-based paints, and differing regulatory perspectives on dredging benefits-the City remains on track to meet TMDL milestones through continued monitoring, outreach, and adaptive management. These efforts support the City’s commitment to maintaining Newport Harbor as a clean, safe, and well-enjoyed resource.
RECOMMENDATION:
1. Determine this action is exempt from the California Environmental Quality Act (CEQA) pursuant to Sections 15060(c)(2) and 15060(c)(3) of the CEQA Guidelines because this action will not result in a physical change to the environment, directly or indirectly; and
2. Receive and file