San Diego Region - Shelter Island Yacht Basin Copper TMDL

Shelter Island Yacht Basin Dissolved Copper TMDL

The San Diego Water Board adopted the Shelter Island Yacht Basin (SIYB) TMDL for Dissolved Copper on February 9, 2005. The State Water Resources Control Board and the Office of Administrative Law approved the TMDL on September 22, 2005 and December 2, 2005, respectively. The USEPA granted final approval of the TMDL on February 8, 2006. After receipt of all approvals the SIYB TMDL was incorporated into Chapter 7 of the Basin Plan.

SIYB is a popular recreational marina located in the north end of San Diego Bay. Copper used in antifouling paints to prevent buildup of marine organisms on a vessel's hull can leach into the environment where, even at low concentrations, is toxic to a variety of aquatic organisms, and is persistent in the environment. The combination of the large number of recreational vessels and reduced tidal flushing at SIYB has resulted in concentrations of dissolved copper that exceed numeric water quality objectives for dissolved copper and narrative water quality objectives for toxicity and pesticides. These exceedances threaten wildlife and marine habitat beneficial uses. The SIYB was placed on the 1996 Clean Water Act Section 303(d) List of Water Quality Limited Segments for dissolved copper.

TMDL Documents

Implementation of the Shelter Island Yacht Basin Dissolved Copper TMDL

The SIYB TMDL has the following compliance schedule:

Time Period Percent Reduction from Initial
Estimated Loading
Reduction to be Attained by End of Year Estimated Interim & Final Target Loading
(kg/year of Dissolved Copper)
Stage 1 2005 - 2007 0 % N/A N/A
Stage 2 2007 - 2012 10 % 7 1,900
Stage 3 2012 - 2017 40 % 12 1,300
Stage 4 2017 - 2022 76 % 17 567

The Unified Port of San Diego (Port District) is implementing the SIYB TMDL through its Copper Reduction Program. The Port District, through its Hull Paint Conversion Program, is actively working with Shelter Island Yacht Basin boaters to convert copper hull paint to non-biocide hull paints. Through its Monitoring and Data Assessment Program, the Port District also conducts special studies and a monitoring program to evaluate the effectivness of the Hull Paint Conversion Program and the attainment of the reductions required by the SIYB TMDL.

Stakeholder Involvement

Stakeholder TMDL Implementation Meeting, August 13, 2007



For Additional Information

Please contact Ms. Cynthia Gorham 619 521-3921 or by email at