Copper in San Diego's Water
Copper finds its way into our waters through stormwater runoff, industrial processes and boat hull paint leaching. The San Diego Regional Water Board developed the Shelter Island Yacht Basin (SIYB) Total Maximum Daily Load (TMDL) for dissolved copper to address poor water quality there.
Coastkeeper works with the Port of San Diego, recreational and commercial boaters, marina owners and other interested groups to implement the reductions called for in the TMDL.
Boats are typically painted with copper-based antifouling paints to prevent buildup of marine organisms on a vessel's hull. The copper in antifouling paints is designed to leach into the water to prevent marine fouling. However, even at relatively low levels, copper is toxic to a variety of aquatic organisms, not just fouling organisms, and is persistent in the environment. The large number of boats at the marina and the relatively small tidal action has resulted in elevated levels of dissolved copper that exceed water quality objectives and threaten wildlife and marine habitat.
Coastkeeper works with the Port of San Diego to develop a three-pronged approach to address the copper pollution, including a state initiative, research on “clean” paints and local implementation including paint and topside management strategies. We support the Port’s work to convert up to 300 boats to non-copper based alternatives.