Backflow Preventer Installations by San Diego Unified Port District at Tenth Avenue Marine Terminal and National City Marine Terminal

The proposed project would involve the removal of existing drainage facilities and installation of three (3) storm drain back flow preventers by San Diego Unified Port District (District) in the cities of San Diego, California and National City, California. The project proposes the installation of backflow preventers at storm drain outfalls in two locations: National City Marine Terminal (NCMT) and Tenth Avenue Marine Terminal (TAMT). Two (2) of the three installations would occur at NCMT and one (1) would occur at TAMT. Additional work for this project would include minor trenching and backfill for installation of the improvements, minor repaving of trenched areas, and added cleanouts and manholes for improved access and maintenance. Work to specifically complete the proposed project is outlined below: TAMT The backflow preventer at TAMT outfall T4-2.1 would be a 33-inch diameter in-line check valve, installed within the existing 33-inch diameter reinforced concrete pipe (RCP) storm drain, and between two (2) proposed Type A storm drain cleanouts. NCMT The first backflow preventer at NCMT outfall 004.1 would be a 30-inch diameter in-line check valve, installed within the existing 30-inch diameter RCP storm drain. It would be located approximately 8 inches from the face of the upstream cleanout and between two (2) proposed Type A storm drain cleanouts. The second backflow preventer at NCMT outfall 1003.1 would be a 72-inch diameter in-line check valve. The valve would be installed within the existing 72-inch RCP storm drain, approximately 2 feet from the face of the proposed modified 6x8 foot type B8 inlet. Additional work at this location would include replacement of the existing Type B8 inlet with a 6’x8’ modified Type B cleanout. The District would ensure the exiting grade and drainage pattern match the existing conditions. The proposed project requires the implementation of a traffic control plan during construction. Access to the terminals would not be affected as the construction area is limited and would be cordoned off. Equipment staging is to occur on-site but out of the way of working facilities as to not impact normal terminal operations. Port Maritime Operations has reviewed the proposed project plans and have not expressed concern with staging location or impacts to terminal operations. Construction of the proposed project is anticipated to occur in approximately March 2025 and would take approximately 7 months to complete. Hours of construction would be from 7:00 AM – 3:30 PM, Monday through Friday, unless otherwise requested and approved. 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 District would be responsible for complying with all applicable federal, state, and local laws regarding construction demolition debris, hazards and hazardous materials, and stormwater.