The San Diego Unified Port District (Applicant) proposes to conduct a pilot study to temporarily pause in-water hull cleaning (IWHC) activities for vessels with copper-based paint in the Shelter Island Yacht Basin (SIYB) for an eight-week period to explore the relationship between IWHC activities and water quality conditions. In 2005, the San Diego Regional Water Quality Control Board (RWQCB) set a Dissolved Copper Total Maximum Daily Load (TMDL) for the Shelter Island Yacht Basin (SIYB) with a target 76 percent reduction of copper loading by 2022. The RWQCB attributed approximately 98 percent of all copper loading to SIYB to copper-based antifouling paints applied to the hulls of recreational boats. Passive leaching of copper from boat hulls and IWHC of the copper-based antifouling paints were identified as the primary mechanisms for the copper loading into the water.
During the proposed pilot study, IWHC activities would be paused during the eight-week period. This would involve a proposed amendment to Article 4.14 of the District Code, “Regulation of In-Water Hull Cleaning,” to implement the temporary pause. Water quality samples would be collected weekly throughout the SIYB in three phases: four weeks prior to the pilot study, during the eight-week pilot study, and four weeks following the pilot study. The water quality samples would be analyzed to measure dissolved and total copper concentrations in SIYB. The proposed pilot study is anticipated to occur Winter 2021/2022 (approximately mid-December 2021 – mid-February 2022).
Due to its nature and limited scope, construction of the proposed project would generate a minor amount of vehicle trips and would require limited use of equipment. Therefore, impacts related to air quality, greenhouse gas emissions, and transportation and traffic are not anticipated to occur. Furthermore, the Applicant would be responsible for complying with all applicable federal, state, and local laws regarding construction demolition debris, hazards and hazardous materials, and stormwater.