California Code of Regulations › Title 23 - Waters › Division 4 - Regional Water Quality Control Boards › Chapter 1 - Water Quality Control Plans, Policies, and Guidelines › Article 9 - San Diego Region › Section 3989.2 - Total Maximum Daily Load for Dissolved Copper in Shelter Island Yacht Basin

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
Resolution No. R9-2005-0019, adopted on February 9, 2005 by
					 the San Diego Regional Water Quality Control Board (San Diego Water Board),
					 modified the regulatory provisions of the Water Quality Control Plan for the
					 San Diego Basin by establishing a Total Maximum Daily Load (TMDL) for Dissolved
					 Copper in Shelter Island Yacht Basin (SIYB), San Diego Bay.
The TMDL addresses toxicity in SIYB caused primarily by
					 copper-based antifouling paints. The numeric targets were set equal to water
					 quality criteria for dissolved copper as set forth by the U.S. Environmental
					 Protection Agency in the California Toxics Rule to protect aquatic life from
					 acute and chronic toxicity. The numeric target for dissolved copper is 3.1
					 micrograms/liter (µg/L) for continuous or chronic exposure (4-day
					 average) and 4.8 µg/L (1-hour average) for maximum or acute exposures,
					 not to be exceeded more than once every three years.
The TMDL was calculated to be 567 kilograms/year of
					 dissolved copper, amounting to a 76 percent reduction in current loading from
					 copper-based antifouling paints. Most of the load reduction will be required
					 from passive leaching, as well as to a lesser extent from underwater hull
					 cleaning of copper-based antifouling paints.
The dischargers responsible for meeting the copper
					 reductions and allocations are the San Diego Unified Port District, marina
					 owners and operators at SIYB, boat owners at SIYB, underwater hull cleaners at
					 SIYB, and the City of San Diego.
In order to implement the TMDLs, the San Diego Water Board
					 will (1) coordinate with governmental agencies having legal authority over the
					 use of copper-based antifouling paints, which are registered pesticides; (2)
					 regulate the discharge of copper to SIYB waters through the issuance of Waste
					 Discharge Requirements (WDRs), Waivers of WDRs, and/or adoption of Waste
					 Discharge Prohibitions; and (3) amend Order No. 2001-01, "Waste Discharge
					 Requirements for Discharges of Urban Runoff from the Municipal Separate Storm
					 Sewer Systems" to require that discharges of copper into SIYB waters not
					 increase via the City of San Diego's municipal separate storm sewer system from
					 existing loadings. Compliance with the allocations will be required over a
					 17-year staged compliance schedule. The first stage consists of an initial
					 2-year orientation period during which no copper load reductions are required.
					 The subsequent 15 year reduction period is comprised of three stages during
					 which incremental copper load reductions are required as shown below.
Table 1. Interim Loading Targets for Attainment of
					 the TMDL
Stage
Time Period
Percent Reduction from Current
							 Estimated Loading
Reduction to be Attained by End of
							 Year
Estimated Interim Target Loading
							 (kg/year of dissolved Cu)
Stage 1
Years 1-2
0%
N/A
N/A
Stage 2
Years 2-7
10%
7
1,900
Stage 3
Years 7-12
40%
12
1,300
Stage 4
Years 12-17
76%
17
567
1. New
					 section summarizing amendments to Water Quality Control Plan for the San Diego
					 Region filed 12-2-2005; amendments adopted by San Diego Regional Water Quality
					 Control Board Resolution No. R9-2005-0019 2-9-2005; approved by OAL and
					 operative 12-2-2005 pursuant to Government Code section
					 11353
					 (Register 2005, No. 48).