Copper and nickel listings are based on the possible impairment of estuarine beneficial uses, including fish spawning and estuarine habitat. Regional Monitoring Program data show that copper and nickel concentrations exceed threshold toxicities for sensitive aquatic indicator species, including organisms used to derive US EPA’s National Toxics Rule (NTR) criteria. Dissolved copper concentrations exceed the draft California Toxic Rule (CTR) saltwater criterion more than half of the times sampled in South San Francisco Bay. When the CTR is promulgated, the dissolved criteria will become the default water quality objectives for all Bay segments, unless USEPA approves site specific objectives.
The Regional Board is using the Santa Clara Basin Watershed Management Initiative as a stakeholder forum for development of a TMDL for copper and nickel in South San Francisco Bay, including consideration of a site specific objectives for copper and nickel. Studies conducted by the City of San Jose in accordance with USEPA guidance to support a site specific objectives are currently being reviewed.